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Электронный компонент: ADAV801

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Audio Codec for Recordable DVD
ADAV801
Rev. 0
Information furnished by Analog Devices is believed to be accurate and reliable.
However, no responsibility is assumed by Analog Devices for its use, nor for any
infringements of patents or other rights of third parties that may result from its use.
Specifications subject to change without notice. No license is granted by implication
or otherwise under any patent or patent rights of Analog Devices. Trademarks and
registered trademarks are the property of their respective owners.
One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
Tel: 781.329.4700
www.analog.com
Fax: 781.326.8703
2004 Analog Devices, Inc. All rights reserved.
FEATURES
Stereo analog-to-digital converter (ADC)
Supports 48/96 kHz sample rates
102 dB dynamic range
Single-ended input
Automatic level control
Stereo digital-to-analog converter (DAC)
Supports 32/44.1/48/96/192 kHz sample rates
101 dB dynamic range
Single-ended output
Asynchronous operation of ADC and DAC
Stereo sample rate converter (SRC)
Input/output range: 8 kHz to 192 kHz
140 dB dynamic range
Digital interfaces
Record
Playback
Auxiliary record
Auxiliary playback
S/PDIF (IEC60958) input and output
Digital interface receiver (DIR)
Digital interface transmitter (DIT)
PLL-based audio MCLK generators
Generates required DVDR system MCLKs
Device control via SPI-compatible serial port
64-lead LQFP package
FUNCTIONAL BLOCK DIAGRAM
ANALOG-TO-DIGITAL
CONVERTER
REFERENCE
SRC
DIGITAL-TO-ANALOG
CONVERTER
ADAV801
DIT
AUX DATA
OUTPUT
RECORD
DATA
OUTPUT
CONTROL
REGISTERS
PLL
DIGITAL
INPUT/OUTPUT
SWITCHING MATRIX
(DATAPATH)
PLAYBACK
DATA INPUT
AUX DATA
INPUT
DIR
VINL
VINR
VREF
FILTD
IAUXL
RCL
K
IAUXBCL
K
IAUXSDAT
A
DIRIN
OLRCLK
OBCLK
OSDATA
OAUXLRCLK
OAUXBCLK
OAUXSDATA
DITOUT
CO
UT
CIN
CCL
K
CL
AT
CH
SYSCL
K
3
SYSCL
K
2
SYSCL
K
1
ZEROL/INT
ZEROR
MCL
K
I
XOUT
XIN
MCL
K
O
VOUTL
VOUTR
04577-0-001
IL
RCL
K
IBCL
K
ISDAT
A
Figure 1.
APPLICATIONS
DVD-recordable
All formats
CD-R/W
PRODUCT OVERVIEW
The ADAV801 is a stereo audio codec intended for applications
such as DVD or CD recorders that require high performance
and flexible, cost-effective playback and record functionality.
The ADAV801 features Analog Devices' proprietary, high
performance converter cores to provide record (ADC), playback
(DAC), and format conversion (SRC) on a single chip. The
ADAV801 record channel features variable input gain to allow
for adjustment of recorded input levels and automatic level
control, followed by a high performance stereo ADC whose
digital output is sent to the record interface. The record channel
also features level detectors that can be used in feedback loops
to adjust input levels for optimum recording. The playback
channel features a high performance stereo DAC with
independent digital volume control.
The sample rate converter (SRC) provides high performance
sample rate conversion to allow inputs and outputs that require
different sample rates to be matched. The SRC input can be
selected from playback, auxiliary, DIR, or ADC (record). The
SRC output can be applied to the playback DAC, both main and
auxiliary record channels, and a DIT.
Operation of the ADAV801 is controlled via an SPI-compatible
serial interface, which allows the programming of individual
control register settings. The ADAV801 operates from a single
analog 3.3 V power supply and a digital power supply of 3.3 V
with optional digital interface range of 3.0 V to 3.6 V.
The part is housed in a 64-lead LQFP package and is character-
ized for operation over the commercial temperature range of
-40C to +85C.
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ADAV801
Rev. 0 | Page 2 of 56
TABLE OF CONTENTS
Specifications..................................................................................... 3
Test Conditions............................................................................. 3
ADAV801 Specifications ............................................................. 3
Timing Specifications .................................................................. 6
Temperature Range ...................................................................... 7
Absolute Maximum Ratings............................................................ 8
ESD Caution.................................................................................. 8
Pin Configuration and Function Descriptions............................. 9
Typical Performance Characteristics ........................................... 11
Functional Description .................................................................. 15
ADC Section ............................................................................... 15
DAC Section................................................................................ 18
Sample Rate Converter (SRC) Functional Overview ............ 19
PLL Section ................................................................................. 22
SPDIF Transmitter and Receiver.............................................. 23
Serial Data Ports ......................................................................... 27
Interface Control ............................................................................ 30
SPI Interface ................................................................................ 30
Block Reads and Writes ............................................................. 30
Layout Considerations................................................................... 54
ADC ............................................................................................. 54
DAC.............................................................................................. 54
PLL ............................................................................................... 54
Reset and Power-Down Considerations ................................. 54
Outline Dimensions ....................................................................... 55
Ordering Guide .......................................................................... 55
REVISION HISTORY
7/04--Revision 0: Initial Version
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ADAV801
Rev. 0 | Page 3 of 56
SPECIFICATIONS
TEST CONDITIONS
Test conditions, unless otherwise noted.
Table 1.
Test Parameter
Condition
Supply Voltage
Analog 3.3
V
Digital 3.3
V
Ambient Temperature
25C
Master Clock (XIN)
12.288 MHz
Measurement Bandwidth
20 Hz to 20 kHz
Word Width (All Converters)
24 bits
Load Capacitance on Digital Outputs
100 pF
ADC Input Frequency
1007.8125 Hz at -1 dBFS
DAC Output Frequency
960.9673 Hz at 0 dBFS
Digital Input
Slave Mode, I
2
S Justified Format
Digital Output
Slave Mode, I
2
S Justified Format
ADAV801 SPECIFICATIONS
Table 2.
Parameter Min
Typ
Max
Unit
Comments
PGA SECTION
Input Impedance
4
k
Minimum Gain
0
dB
Maximum Gain
24
dB
Gain Step
0.5
dB
REFERENCE SECTION
Absolute Voltage, V
REF
1.5
V
V
REF
Temperature Coefficient
80
ppm/C
ADC SECTION
Number of Channels
2
Resolution
24
Bits
Dynamic Range
-60 dB input
Unweighted
99
dB
f
S
= 48 kHz
98
dB
f
S
= 96 kHz
A-Weighted 98
102
dB
f
S
= 48 kHz
101
dB
f
S
= 96 kHz
Total Harmonic Distortion plus Noise
Input = -1.0 dBFS
-88
dB
f
S
= 48 kHz
-87
dB
f
S
= 96 kHz
Analog Input
Input Range ( Full Scale)
1.0
V rms
DC Accuracy
Gain Error
-1.5
-0.8
dB
Interchannel Gain Mismatch
0.05
dB
Gain Drift
1
mdB/C
Offset
-10
mV
Crosstalk (EIAJ Method)
-110
dB
Volume Control Step Size (256 Steps)
0.39
% per
step
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ADAV801
Rev. 0 | Page 4 of 56
Parameter Min
Typ
Max
Unit
Comments
Maximum Volume Attenuation
-48
dB
Mute Attenuation
dB
ADC outputs all zero codes
Group Delay
f
S
= 48 kHz
910
s
f
S
= 96 kHz
460
s
ADC LOW-PASS DIGITAL DECIMATION FILTER CHARACTERISTICS
1
Pass-Band Frequency
22
kHz
Sample rate: 48 kHz
44
kHz
Sample rate: 96 kHz
Stop-Band Frequency
26
kHz
Sample rate: 48 kHz
52
kHz
Sample rate: 96 kHz
Stop-Band Attenuation
120
dB
Sample rate: 48 kHz
120
dB
Sample rate: 96 kHz
Pass-Band Ripple
0.01
dB
Sample rate: 48 kHz
0.01
dB
Sample rate: 96 kHz
ADC HIGH-PASS DIGITAL FILTER CHARACTERISTICS
Cutoff Frequency
0.9
Hz
f
S
= 48 kHz
SRC SECTION
Resolution
24
Bits
Sample Rate
8
192
kHz
XIN = 27 MHz
SRC MCLK
138 f
S-MAX
33
MHz
f
S-MAX
is the greater of the input
or output sample rate
Maximum Sample Rate Ratios
Upsampling
1:8
Downsampling
7.75:1
Dynamic Range
140
20 Hz to f
S
/2, 1 kHz,
-60 dBFS input, f
IN
= 44.1 kHz,
f
OUT
= 48 kHz
Total Harmonic Distortion plus Noise
120
dB
20 Hz to f
S
/2, 1 kHz,
0 dBFS input, f
IN
= 44.1 kHz,
f
OUT
= 48 kHz
DAC SECTION
Number of Channels
2
Resolution
24
Bits
Dynamic Range
20 Hz to 20 kHz, -60 dB input
Unweighted
99
dB f
S
= 48 kHz
98
dB f
S
= 96 kHz
A-Weighted 97
101
dB f
S
= 48 kHz
100
dB f
S
= 96 kHz
Total Harmonic Distorton plus Noise
Referenced to 1 V rms
-91
dB f
S
= 48 kHz
-90
dB f
S
= 96 kHz
Analog Outputs
Output Range ( Full Scale)
1.0
V rms
Output Resistance
60
Common-Mode Output Voltage
1.5
V
DC Accuracy
Gain Error
-2
-0.8
dB
Interchannel Gain Mismatch
0.05
dB
Gain Drift
1
mdB/C
DC Offset
-30
+30
mV
Crosstalk (EIAJ Method)
-110
dB
Phase Deviation
0.05
Degrees
Mute Attenuation
-95.625
dB
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ADAV801
Rev. 0 | Page 5 of 56
Parameter Min
Typ
Max
Unit
Comments
Volume Control Step Size (256 Steps)
0.375
dB
Group Delay
48 kHz
630
s
96 kHz
155
s
192 kHz
66
s
DAC LOW-PASS DIGITAL INTERPOLATION FILTER CHARACTERISTICS
Pass-Band Frequency
20
kHz
Sample rate: 44.1 kHz
22
kHz
Sample rate: 48 kHz
42
kHz
Sample rate: 96 kHz
Stop-Band Frequency
24
kHz
Sample rate: 44.1 kHz
26
kHz
Sample rate: 48 kHz
60
kHz
Sample rate: 96 kHz
Stop-Band Attenuation
70
dB
Sample rate: 44.1 kHz
70
dB
Sample rate: 48 kHz
70
dB
Sample rate: 96 kHz
Pass-Band Ripple
0.002
dB
Sample rate: 44.1 kHz
0.002
dB
Sample rate: 48 kHz
0.005
dB
Sample rate: 96 kHz
PLL SECTION
Master Clock Input Frequency
27/54
MHz
Generated System Clocks
MCLKO
27/54
MHz
SYSCLK1 256
768
f
S
256/384/512/768 32/44.1/
48 kHz
SYSCLK2 256
768
f
S
256/384/512/768 32/44.1/
48 kHz
SYSCLK3 256
512
f
S
256/512 32/44.1/48 kHz
Jitter
SYSCLK1
65
ps
rms
SYSCLK2
75
ps
rms
SYSCLK3
75
ps
rms
DIR SECTION
Input Sample Frequency
27.2
200
kHz
Differential Input Voltage
200
mV
DIT SECTION
Output Sample Frequency
27.2
200 kHz
DIGITAL I/O
Input Voltage High, V
IH
2.0
DVDD V
Input Voltage Low, V
IL
0.8 V
Input Leakage, I
IH
@ V
IH
= 3.3 V
10 A
Input Leakage, I
IL
@ V
IL
= 0 V
10 A
Output Voltage High, V
OH
@ I
OH
= 0.4 mA
2.4
V
Output Voltage Low, V
OL
@ I
OL
= -2 mA
0.4 V
Input Capacitance
15 pF
POWER
Supplies
Voltage, AVDD
3.0
3.3
3.6
V
Voltage, DVDD
3.0
3.3
3.6
V
Voltage, ODVDD
3.0
3.3
3.6
V
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ADAV801
Rev. 0 | Page 6 of 56
Parameter Min
Typ
Max
Unit
Comments
Operating Current
All supplies at 3.3 V
Analog Current
60
mA
Digital Current
38
mA
Digital Interface Current
13
mA
DIRIN/DIROUT Current
5
mA
PLL Current
18
mA
Power-Down Current
RESET low, no MCLK
Analog Current
18
mA
Digital Current
2.5
mA
Digital Interface Current
700
A
DIRIN/DIROUT Current
3.5
mA
PLL Current
900
A
Power Supply Rejection
Signal at Analog Supply Pins
-70
dB
1 kHz, 300 mV p-p
-70
dB
20 kHz, 300 mV p-p
1
Guaranteed by design.
TIMING SPECIFICATIONS
Timing specifications are guaranteed over the full temperature and supply range.
Table 3.
Parameter
Min
Typ
Max
Unit
Comments
MASTER CLOCK AND RESET
f
MCLK
MCLKI Frequency
12.288
54
MHz
f
XIN
XIN Frequency
27.0
54
MHz
t
RESET
RESET Low
20
ns
SPI PORT
t
CCH
CCLK High
40
ns
t
CCL
CCLK Low
40
ns
t
CIS
CIN Setup
10
ns
To CCLK rising edge
t
CIH
CIN Hold
10
ns
From CCLK rising edge
t
CLS
CLATCH Setup
10
ns
To CCLK rising edge
t
CLH
CLATCH Hold
10
ns
From CCLK rising edge
t
COE
COUT Enable
15
ns
From CLATCH falling edge
t
COD
COUT Delay
20
ns
From CCLK falling edge
t
COTS
COUT Three-State
25
ns
From CLATCH rising edge
SERIAL PORTS
1
Slave Mode
t
SBH
xBCLK High
40
ns
t
SBL
xBCLK Low
40
ns
f
SBF
xBCLK Frequency
64 f
S
t
SLS
xLRCLK Setup
10
ns
To xBCLK rising edge
t
SLH
xLRCLK Hold
10
ns
From xBCLK rising edge
t
SDS
xSDATA Setup
10
ns
To xBCLK rising edge
t
SDH
xSDATA Hold
10
ns
From xBCLK rising edge
t
SDD
xSDATA Delay
10
ns
From xBCLK falling edge
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ADAV801
Rev. 0 | Page 7 of 56
Parameter
Min
Typ
Max
Unit
Comments
Master Mode
t
MLD
xLRCLK Delay
5
ns
From xBCLK falling edge
t
MDD
xSDATA Delay
10
ns
From xBCLK falling edge
t
MDS
xSDATA Setup
10
ns
From xBCLK rising edge
t
MDH
xSDATA Hold
10
ns
From xBCLK rising edge
1
The prefix x refers to I-, O-, IAUX-, or OAUX- for the full pin name.
TEMPERATURE RANGE
Table 4.
Min
Typ
Max
Unit
Specifications Guaranteed
25
C
Functionality Guaranteed
-40
+85
C
Storage -65
+150
C
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ADAV801
Rev. 0 | Page 8 of 56
ABSOLUTE MAXIMUM RATINGS
Table 5.
Parameter Rating
DVDD to DGND and ODVDD to
DGND
0 V to 4.6 V
AVDD to AGND
0 V to 4.6 V
Digital Inputs
DGND - 0.3 V to DVDD + 0.3 V
Analog Inputs
AGND - 0.3 V to AVDD + 0.3 V
AGND to DGND
-0.3 V to +0.3 V
Reference Voltage
Indefinite short circuit to ground
Soldering (10 s)
300C
Stresses above those listed under Absolute Maximum Ratings
may cause permanent damage to the device. This is a stress
rating only; functional operation of the device at these or any
other conditions above those indicated in the operational
section of this specification is not implied. Exposure to absolute
maximum rating conditions for extended periods may affect
device reliability.
ESD CAUTION
ESD (electrostatic discharge) sensitive device. Electrostatic charges as high as 4000 V readily accumulate on
the human body and test equipment and can discharge without detection. Although this product features
proprietary ESD protection circuitry, permanent damage may occur on devices subjected to high energy
electrostatic discharges. Therefore, proper ESD precautions are recommended to avoid performance
degradation or loss of functionality.
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ADAV801
Rev. 0 | Page 9 of 56
PIN CONFIGURATION AND FUNCTION DESCRIPTIONS
NC
VOU
T
L
NC
VOU
T
R
OAUX
S
DATA
IAUX
LRCLK
IAUX
BCLK
IAUX
S
DATA
ZEROL/INT
ZEROR
DVDD
DGND
ADVDD
ADGND
PLL_LF2
PLL_LF1
PLL_GND
PLL_VDD
DGND
SYSCLK1
SYSCLK2
SYSCLK3
XIN
XOUT
39
38
37
41
40
MCLKO
MCLKI
DVDD
DGND
36
35
34
33
42
43
44
45
46
47
48
17 18 19 20 21 22 23 24
ILRCLK
IBCLK
IS
DATA
OLRCLK
OBCLK
OS
DATA
DIRIN
ODVDD
ODGND
DITOUT
OAUX
LRCLK
OAUX
BCLK
1
2
3
4
5
6
7
8
9
10
11
12
64 63 62 61 60 59 58
CAP
LN
CAP
LP
AGND
CAP
RP
CAP
RN
AV
DD
AGND
VR
EF
AGND
FILTD
AGND
AV
DD
VINR
VINL
AGND
AVDD
DIR_LF
DIR_GND
DIR_VDD
RESET
CLATCH
CIN
CCLK
COUT
13
14
15
16
25 26 27
31
30
29
28
32
57 56 55 54 53 52 51 50 49
ADAV801
TOP VIEW
(Not to Scale)
04577-0-002
PIN 1
INDICATOR
NC = NO CONNECT
Figure 2. Pin Configuration
Table 6. Pin Function Descriptions
Pin No.
Mnemonic
I/O
Description
1
VINR
I
Analog Audio Input, Right Channel.
2
VINL
I
Analog Audio Input, Left Channel.
3 AGND
Analog
Ground.
4 AVDD
Analog
Voltage
Supply.
5
DIR_LF
DIR Phase-Locked Loop (PLL) Filter Pin.
6
DIR_GND
Supply Ground for DIR Analog Section. This pin should be connected to AGND.
7
DIR_VDD
Supply for DIR Analog Section. This pin should be connected to AVDD.
8
RESET
I
Asychronous Reset Input (Active Low).
9
CLATCH
I
Chip Select (Control Latch) Pin of SPI-Compatible Control Interface.
10
CIN
I
Data Input of SPI-Compatible Control Interface.
11
CCLK
I
Clock Input of SPI-Compatible Control Interface.
12
COUT
O
Data Output of SPI-Compatible Control Interface.
13 ZEROL/INT
O
Left Channel (Output) Zero Flag or Interrupt (Output) Flag. The function of this pin is determined
by the INTRPT pin in DAC Control Register 4.
14
ZEROR
O
Right Channel (Output) Zero Flag.
15
DVDD
Digital Voltage Supply.
16 DGND
Digital
Ground.
17 ILRCLK
I/O
Sampling
Clock
(LRCLK) of Playback Digital Input Port.
18
IBCLK
I/O
Serial Clock (BCLK) of Playback Digital Input Port.
19
ISDATA
I
Data Input of Playback Digital Input Port.
20 OLRCLK
I/O
Sampling
Clock
(LRCLK) of Record Digital Output Port.
21
OBCLK
I/O
Serial Clock (BCLK) of Record Digital Output Port.
22
OSDATA
O
Data Output of Record Digital Output Port.
23
DIRIN
I
Input to Digital Input Receiver (S/PDIF).
24
ODVDD
Interface Digital Voltage Supply.
25
ODGND
Interface Digital Ground.
26
DITOUT
O
S/PDIF Output from DIT.
27 OAUXLRCLK
I/O
Sampling
Clock
(LRCLK) of Auxiliary Digital Output Port.
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ADAV801
Rev. 0 | Page 10 of 56
Pin No.
Mnemonic
I/O
Description
28
OAUXBCLK
I/O
Serial Clock (BCLK) of Auxiliary Digital Output Port.
29
OAUXSDATA
O
Data Output of Auxiliary Digital Output Port.
30
IAUXLRCLK
I/O
Sampling Clock (LRCLK) of Auxiliary Digital Input Port.
31
IAUXBCLK
I/O
Serial (BCLK) of Auxiliary Digital Input Port.
32
IAUXSDATA
I
Data Input of Auxiliary Digital Input Port.
33 DGND
Digital
Ground.
34
DVDD
Digital Supply Voltage.
35
MCLKI
I
External MCLK Input.
36 MCLKO
O
Oscillator
Output.
37 XOUT
I Crystal
Input.
38
XIN
I
Crystal or External MCLK Input.
39
SYSCLK3
O
System Clock 3 (from PLL2).
40
SYSCLK2
O
System Clock 2 (from PLL2).
41
SYSCLK1
O
System Clock 1 (from PLL1).
42 DGND
Digital
Ground.
43
PLL_VDD
Supply for PLL Analog Section. This pin should be connected to AVDD.
44
PLL_GND
Ground for PLL Analog Section. This pin should be connected to AGND.
45
PLL_LF1
Loop Filter for PLL1.
46
PLL_LF2
Loop Filter for PLL2.
47
ADGND
Analog Ground (Mixed Signal). This pin should be connected to AGND.
48
ADVDD
Analog Voltage Supply (Mixed Signal). This pin should be connected to AVDD.
49
VOUTR
O
Right Channel Analog Output.
50 NC No
Connect.
51
VOUTL
O
Left Channel Analog Output.
52 NC No
Connect.
53 AVDD
Analog
Voltage
Supply.
54 AGND
Analog
Ground.
55
FILTD
Output DAC Reference Decoupling.
56 AGND
Analog
Ground.
57
VREF
Voltage Reference Voltage.
58 AGND
Analog
Ground.
59 AVDD
Analog
Voltage
Supply.
60
CAPRN
ADC Modulator Input Filter Capacitor (Right Channel, Negative).
61
CAPRP
ADC Modulator Input Filter Capacitor (Right Channel, Positive).
62 AGND
Analog
Ground.
63
CAPLP
ADC Modulator Input Filter Capacitor (Left Channel, Positive).
64
CAPLN
ADC Modulator Input Filter Capacitor (Left Channel, Negative).
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ADAV801
Rev. 0 | Page 11 of 56
TYPICAL PERFORMANCE CHARACTERISTICS
FREQUENCY (Normalized to f
S
)
MAGNITUDE
(dB)
0
50
100
150
0
0.5
1.0
1.5
2.0
04577-0-037
Figure 3. ADC Composite Filter Response
FREQUENCY (Hz)
MAGNITUDE
(dB)
5
5
0
15
10
25
20
30
0
5
10
15
20
04577-0-038
Figure 4. ADC High-Pass Filter Response, f
S
= 48 kHz
FREQUENCY (Hz)
MAGNITUDE
(dB)
5
5
0
15
10
25
20
30
0
5
10
15
20
04577-0-039
Figure 5. ADC High-Pass Filter Response, f
S
= 96 kHz
FREQUENCY (kHz)
MAGNITUDE
(dB)
0
50
100
150
0
96
192
288
384
04577-0-040
Figure 6. DAC Composite Filter Response, 48 kHz
FREQUENCY (kHz)
MAGNITUDE
(dB)
0
50
100
150
0
24
12
36
48
04577-0-041
Figure 7. DAC Pass-Band Filter Response, 48 kHz
FREQUENCY (kHz)
MAGNITUDE
(dB)
0.06
0.04
0.02
0.00
0.06
0.04
0.02
0
8
16
24
04577-0-042
Figure 8. DAC Filter Ripple, 48 kHz
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ADAV801
Rev. 0 | Page 12 of 56
FREQUENCY (kHz)
MAGNITUDE
(dB)
0
50
100
150
0
192
384
576
768
04577-0-043
Figure 9. DAC Composite Filter Response, 96 kHz
FREQUENCY (kHz)
MAGNITUDE
(dB)
0
50
100
150
0
24
48
72
9
04577-0-044
6
Figure 10. DAC Pass-Band Filter Response, 96 kHz
FREQUENCY (kHz)
MAGNITUDE
(dB)
0.10
0.05
0.00
0.05
0.10
0
24
48
72
9
04577-0-045
6
Figure 11. DAC Filter Ripple, 96 kHz
FREQUENCY (kHz)
MAG
N
ITUDE
(dB)
0
50
100
150
200
0
384
768
1152
1536
04577-0-046
Figure 12. DAC Composite Filter Response, 192 kHz
FREQUENCY (kHz)
MAGNITUDE
(dB)
0
2
4
6
8
10
48
64
80
96
04577-0-047
Figure
2 kHz
13. DAC Pass-Band Filter Response, 19
FREQUENCY (kHz)
MAGNITUDE
(dB)
0.50
0.40
0.30
0.20
0.10
0.00
0.10
0.30
0.40
0.20
0.50
0
8
16
32
64
04577-0-048
Figure 14. DAC Fil r Ripple, 192 kHz
te
background image
ADAV801
Rev. 0 | Page 13 of 56
FREQUENCY (kHz)
MAGNITUDE
(dB)
0
20
40
80
100
60
120
140
160
0
2
4
6
8
10
12
14
16
18
20
04577-0-049
DNR = 102dB
(A-Weighted)
Fig
Hz
ure 15. DAC Dynamic Range, f
S
= 48 k
FREQUENCY (kHz)
MAGNITUDE
(dB)
0
20
40
80
100
60
120
140
160
0
2
4
6
8
10
12
14
16
18
20
04577-0-050
THD+N = 96dB
Figure 16. DAC THD + N, f
S
= 48 kHz
FREQUENCY (kHz)
MAGNITUDE
(dB)
0
20
40
80
100
60
120
140
160
0
5
10
15
20
25
30
35
40
45 48
04577-0-051
DNR = 102dB
(A-Weighted)
Figure 17. DAC Dynamic Range, f
S
= 96 kHz
FREQUENCY (kHz)
MAGNITUDE
(dB)
0
20
40
80
100
60
120
140
160
0
5
10
15
20
25
30
35
40
45 48
04577-0-052
THD+N = 95dB
Figure 18. DAC THD + N, f
S
= 96 kHz
FREQUENCY (kHz)
MAGNITUDE
(dB)
0
20
40
80
100
60
120
140
160
0
5
10
15
20
04577-0-053
DNR = 102dB
(A-Weighted)
Figure 19. ADC Dynam c Range, f
S
= 48 kHz
i
FREQUENCY (kHz)
MAGNITUDE
(dB)
0
20
40
80
100
60
120
140
160
0
5
10
15
20
04577-0-054
THD+N = 92dB
(V
IN
= 3dB)
Figure 20. DAC THD + N, f
S
= 48 kHz
background image
ADAV801
Rev. 0 | Page 14 of 56
FREQUENCY (kHz)
160
0
8
16
24
32
40
48
04577-0-055
MAGNITUDE
(dB)
40
80
100
60
120
140
0
20
DNR = 102dB
(A-Weighted)
Figure 21. ADC Dynamic Range, f
S
= 96 kHz
FREQUENCY (kHz)
160
0
8
16
24
32
40
48
MAGNITUDE
(dB)
40
80
100
60
0
120
04577-0-056
20
140
TH
(V
D+N = 92dB
IN
= 3dB)
Figure 22. ADC THD + N, f
S
= 96 kHz
background image
ADAV801
Rev. 0 | Page 15 of 56
TION
ck
c
and by a factor of 8 at
he
s
ther the
FUNCTIONAL DESCRIP
ADC SECTION
The ADAV801's ADC section is implemented using a second-
order multibit (5 bits) - modulator. The modulator is
sampled at either half of the ADC MCLK rate (modulator clo
= 128 f
S
) or one-quarter of the ADC MCLK rate (modulator
clock = 64 f
S
). The digital decimator consists of a Sinc^5 filter
followed by a cascade of three half-band FIR filters. The Sin
decimates by a factor of 16 at 48 kHz
96 kHz. Each of the half-band filters decimates by a factor of 2.
Figure 23 shows the details of the ADC section. The ADC can
be clocked by a number of different clock sources to control t
sample rate. MCLK selection for the ADC is set by Internal
Clocking Control Register 1 (Address 0x76). The ADC provide
an output word of up to 24 bits in resolution in twos comple-
ment format. The output word can be routed to ei
output ports, the sample rate converter, or the SPDIF digital
transmitter.
P
LL2
INTE
RNAL
P
LL1
INTE
RNAL
MCLKI
XIN
REG 0x76
BITS 42
DIR P
LL (2
5
6
f
S
)
REG 0x6F
BITS 10
04577-0-003
DIR P
LL (5
1
2
f
S
)
ADC MCLK
DIVIDER
ADC
MCLK
ADC
Figure 23. Clock Path Control on the ADC
Programmable Gain Amplifier (PGA)
The input of the record channel features a PGA that converts
the single-ended signal to a differential signal, which is applied
to the analog - modulator of the ADC. The PGA can be
programmed to amplify a signal by up to 24 dB in 0.5 dB
increments. Figure 24 shows the structure of the PGA circuit.
4k
TO 64k
125
CAPxN
EXTERNAL
CAPACITOR
(1nF NPO)
VREF
TO
MODULATOR
EXTERNAL
CAPACITOR
(1nF NPO)
CAPxP
EXTERNAL
CAPACITOR
(1nF NPO)
8k
8k
04577-0-004
4k
125
Figure 24. PGA Block Diagram
Analog - Modulator
The ADC features a second-order, multibit, - modulator. The
input features two integrators in cascade followed by a flash
converter. This multibit output is directed to a scrambler,
followed by a DAC for loop feedback. The flash ADC outp
also converted from thermometer coding to binary codin
input as a 5-bit word to the decimator. F
ut is
g for
igure 25 shows the
ADC block diagram.
The ADC also features independent digital volume control for
the left and right channels. The volume control consists of
256 linear steps, with each step reducing the digital output
codes by 0.39%. Each channel also has a peak detector that
records the peak level of the input signal. The peak detector
register is cleared by reading it.
ADC MCLK
AMC
(REG 0X63
BIT-7)
MULTIBIT
MODULATOR
DECIMATOR
HPF
PEAK
DETECT
VOLUME
ONTROL
04577-0-005
C
SINC^5
HALF-BAND
FILTER
MODULATOR
CLOCK
(6.144MHz MAX)
384kHz
768kHz
SINC
COMPENSATION
192kHz
384kHz
HALF-BAND
FILTER
96kHz
192kHz
48kHz
96kHz
2
4
Diagram
Figure 25. A
DC Block
background image
ADAV801
Rev. 0 | Page 16 of 56
ALC)
at
e
aximum front end gain.
olume
ADC is still present at the output of the ADC, but scaled by a
value determined by the volume control register.
The ALC block has two functions, attack mode and recover
mode. Recovery mode consists of three settings: no recovery,
normal recovery, and limited recovery. These modes are
discussed in the following sections. Figure 26 is a flow diagram
of the ALC block. When the ALC has been enabled, any changes
made to the PGA or ALC settings are ignored. To change the
functionality of the ALC, it must first be disabled. The settings
can then be changed and the ALC re-enabled.
Attack Mode
When the absolute value of the ADC output exceeds the level
set by the attack threshold bits in ALC Control Register 2, attack
mode is initiated. The PGA gain for both channels is reduced by
one step (0.5 dB). The ALC then waits for a time determined by
the attack timer bits before sampling the ADC output value
again. If the ADC output is still above the threshold, the PGA
gain is reduced by a further step. This procedure continues until
the ADC output is below the limit set by the attack threshold
bits. The initial gains of the PGAs are defined by the ADC left
PGA gain register and the ADC right PGA gain register, and
they can have different values. The ALC subtracts a common
gain offset to these values. The ALC preserves any gain differ-
ence in dB as defined by these registers. At no time do the PGA
gains exceed their initial values. The initial gain setting,
therefore, also serves as a maximum value.
The limit detection mode bit in ALC Control Register 1 deter-
mines how the ALC responds to an ADC output that exceeds
the set limits. If this bit is a 1, then both channels must exceed
the threshold before the gain is reduced. This mode can be used
to prevent unnecessary gain reduction due to spurious noise on
a single channel. If the limit detection mode bit is a 0, the gain is
reduced when either channel exceeds the threshold.
n
is not recovered until the ALC has been reset, either
r by
is
in reduction unnecessarily.
ormal Recovery Mode
Normal recovery mode allows for the PGA gain to be recovered,
provided that the input signal meets certain criteria. First, the
ALC must not be in attack mode, that is, the PGA gain has been
sufficiently such that the input signal is below the level
set by the attack threshold bits. Second, the output result from
the ADC must be below the level set by the recovery threshold
bits in the ALC control register. If both of these criteria are met,
the gain is recovered by one step (0.5 dB). The gain is incremen-
tally restored to its original value, assuming that the ADC
output level is below the recovery threshold at intervals
determined by the recovery time bits.
If the ADC output level exceeds the recovery threshold while
the PGA gain is being restored, the PGA gain value is held and
does not continue restoration until the ADC output level is
again below the recovery threshold. Once the PGA gain is
restored to its original value, it is not changed again unless the
ADC output value exceeds the attack threshold and the ALC
then enters attack mode. Care should be taken when using this
mode to choose values for the attack and recovery thresholds
that prevent excessive volume modulation caused by continuous
gain adjustments.
Limited Recovery Mode
Limited recovery mode offers a compromise between no recov-
ery and normal recovery modes. If the output level of the ADC
exceeds the attack threshold, then attack mode is initiated.
When attack mode has reduced the PGA gain to suitable levels,
the ALC attempts to recover the gain to its original level. If the
ADC output level exceeds the level set by the recovery threshold
bits, a counter is incremented (GAINCNTR). This counter is
incremented at intervals equal to the recovery time selection, if
the ADC has any excursion above the recovery threshold. If the
counter reaches its maximum value, determined by the
GAINCNTR bits in ALC Control Register 1, the PGA gain is
deemed suitable and no further gain recovery is attempted.
Whenever the ADC output level exceeds the attack threshold,
attack mode is reinitiated and the counter is reset.
Automatic Level Control (
The ADC record channel features a programmable automatic
level control block. This block monitors the level of the ADC
output signal and automatically reduces the gain, if the signal
the input pins causes the ADC output to exceed a preset limit.
This function can be useful to maximize the signal dynamic
range when the input level is not well defined. The PGA can b
used to amplify the unknown signal, and the ALC reduces the
gain until the ADC output is within the preset limits. This
results in m
Because the ALC block monitors the output of the ADC, the
volume control function should not be used. The ADC v
control scales the results from the ADC, and any distortion
caused by the input signal exceeding the input range of the
No Recovery Mode
By default, there is no gain recovery. Once the gain has bee
reduced, it
y
reduced
by toggling the ALCEN bit in ALC Control Register 1 o
writing any value to ALC Control Register 3. The latter option
more efficient, because it requires only one write operation to
reset the ALC function. No recovery mode prevents volume
modulation of the signal caused by adjusting the gain, which
can create undesirable artifacts in the signal. The gain can be
reduced but not recovered. Therefore, care should be taken that
spurious signals do not interfere with the input signal, because
these might trigger a ga
N
background image
ADAV801
Rev. 0 | Page 17 of 56
le Rate
-
ecause
ital
ut reduces the oversampling ratio,
cted
o generate a separate 12.288 MHz
eat
Selecting a Samp
The output sample rate of the ADC is always ADC MCLK/256,
as shown in Figure 23. By default, the ADC modulator runs at
ADC MCLK/2. When the ADC MCLK exceeds 12.288 MHz,
the ADC modulator should be set to run at ADC MCLK/4. This
is achieved by setting the AMC (ADC Modulator Clock) bit in
the ADC Control Register 1. To compensate for the reduced
modulator clock speed, a different set of filters are used in the
decimator section ensuring that the sample rate remains
the same.
The AMC bit can also be used to boost the THD + N perform
ance of the ADC at the expense of dynamic range. The
improvement is typically 0.5 dB to 1.0 dB and works, b
selecting the lower modulator rate reduces the amount of dig
noise, improving THD + N, b
therefore reducing the dynamic range by a corresponding
amount.
For best performance of the ADC, avoid using similar
frequency clocks from separate sources in the ADAV801. For
example, running the ADC from a 12.288 MHz clock conne
to MCLKI and using the PLL t
clock for the DAC can reduce the performance of the ADC.
This is due to the interaction of the clocks, which generate b
frequencies that can affect the charge on the switch capacitors
of the analog inputs.
WAIT FOR SAMPLE
WAIT FOR SAMPLE
WAIT FOR SAMPLE
DECREASE GAIN BY 0.5dB
AND WAIT ATTACK TIME
IS SAMPLE
GREATER THAN ATTACK
THRESHOLD?
IS
ABO
THRESHOLD?
IS A RECOVERY
MODE ENABLED?
SAMPLE
VE ATTACK
ARE ALL
SAMPLES BELOW
RECOVERY
THRESHOLD?
HAS GAIN BEEN
FULLY RESTORED?
YES
YES
NO
YES
YES
YES
NO
NO
NORMAL RECOVERY
INCREASE GAIN BY 0.5dB
WAIT RECOVERY TIME
LIMITED RECOVERY
ATTACK MODE
04577-
0-
006
IS SAMPLE
ABOVE ATTACK
THRESHOLD?
ARE ALL
SAMPLES BELOW
RECOVERY
THRESHOLD?
HAS GAIN BEEN
FULLY RESTORED?
IS GAINCNTR
AT MAXIMUM?
YES
NO
NO
YES
YES
YES
NO
NO
INCREASE GAIN BY 0.5dB
NO
INCREMENT
GAINCNTR
NO
NO
NO
HAS RECOVERY
TIME BEEN
REACHED?
HAS RECOVERY
TIME BEEN
REACHED?
Figure 26. ALC Flow Diagram
background image
ADAV801
Rev. 0 | Page 18 of 56
pair
28 steps
ded to remove high
e noise
d
nal
op amps, which might draw more than 50 A or have dynamic
load changes, extra buffering should be used to preserve the
quality of the ADAV801 reference.
The digital input data source for the DAC can be selected from
a number of available sources by programming the appropriate
bits in the datapath control register. Figure 27 shows how the
digital data source and the MCLK source for the DAC are
selected. Each DAC has an independent volume register giving
256 steps of control, with each step giving approximately 0.375
dB of attenuation. Note that the DACs are muted by default to
prevent unwanted pops, clicks, and other noises from appearing
on the outputs while the ADAV801 is being configured. Each
DAC also has a peak-level register that records the peak value of
the digital audio data. Reading the register clears the peak.
electing a Sample Rate
Correct operation of
pon the data rate
S
)
by 2. This prevents the DAC engine from
running too fast. To compensate for the reduced MCLK rate, the
interpolator should be selected to operate in 4 (DAC MCLK =
128 f
S
). Similar combinations can be selected for different
sample rates.
DAC SECTION
S
The ADAV801 has two DAC channels arranged as a stereo
with single-ended analog outputs. Each channel has its own
independently programmable attenuator, adjustable in 1
of 0.375 dB per step. The DAC can receive data from the
playback or auxiliary input ports, the SRC, the ADC, or the DIR.
Each analog output pin sits at a dc level of VREF, and swings
1.0 V rms for a 0 dB digital input signal. A single op amp third-
order external low-pass filter is recommen
frequency noise present on the output pins. Note that the use of
op amps with low slew rate or low bandwidth can cause high
frequency noise and tones to fold down into the audio band.
Care should be taken in selecting these components.
The FILTD and FILTR pins should be bypassed by external
capacitors to AGND. The FILTD pin is used to reduce th
of the internal DAC bias circuitry, thereby reducing the DAC
output noise. The voltage at the VREF pin, FILTR, can be use
to bias external op amps used to filter the output signals. For
applications in which the FILTR is required to drive exter
the DAC is dependent u
provided to the DAC, the master clock applied to the DAC, and
the selected interpolation rate. By default, the DAC assumes that
the MCLK rate is 256 times the sample rate, which requires an
8-times oversampling rate. This combination is suitable for
sample rates of up to 48 kHz.
For a 96 kHz data rate that has a 24.576 MHz MCLK (256 f
associated with it, the DAC MCLK divider should be set to
divide the MCLK
04577-0-007
P
LL2
INTE
RNAL
P
LL1
INTE
RNAL
MCLKI
XIN
REG 0x76
BITS 75
REG 0x65
BITS 32
REG 0x63
BITS 53
DIR P
LL (2
5
6
f
S
)
DIR P
LL (5
1
2
f
S
)
DIR
PLAYBACK
AUXILIARY IN
ADC
MCLK
DIVIDER
DAC
MCLK
DAC
DAC
INPUT
Figure 27. Clock and Datapath Control on the DAC
MULTIBIT
-
MODULATOR
INTERPOLATOR
DAC
DAC
TO ZERO FLAG PINS
FROM DAC
DATAPATH
MULTIPLEXER
VOLUME/MUTE
CONTROL
PEAK
DETECTOR
ZERO DETECT
TO CONTROL
REGISTERS
OUTPUT
04577-0-008
Figure 28. DAC Block Diagram
ANALOG
background image
ADAV801
Rev. 0 | Page 19 of 56
VERVIEW
le rate conversion, data can be
conv
or at
t sam
rates.
The sim
on is to use a zero-order hold between the two
m, T2
tional.
at f
S_OUT
are repeated or dropped, producing
pling process.
t r
S_OUT
ated images from the SIN(x)/x nature of the zero-
orde
es) of the zero-
order h
nfinite
he ratio of T2 to
T1 i
rom the
n never be eliminated. The error can be
he
he
tually interpolated by a factor of 2
20
.
SAMPLE RATE CONVERTER (SRC) FUNCTIONAL O
During asynchronous samp
erted at the same sample rate
differen
ple
plest approach to an asynchronous sample rate
conversi
samplers, as shown in Figure 29. In an asynchronous syste
is never equal to T1, nor is the ratio between T2 and T1 ra
As a result, samples
an error in the resam
The frequency domain shows the wide side lobes tha esult
from this error when the sampling of f
is convolved with
the attenu
r hold. The images at f
S_IN
(dc signal imag
old are i
ly attenuated. Because t
s an irrational number, the error resulting f
resampling at f
S_OUT
ca
significantly reduced, however, through interpolation of t
input data at f
S_IN
. Therefore, the sample rate converter in t
ADAV801 is concep
04577-0-009
SPECTRUM OF
f
S_OUT
SAMPLING
f
S_OUT
2
f
S_OUT
FREQUENCY RESPONSE OF
f
S_OUT
CONVOLVED
WITH ZERO-ORDER HOLD SPECTRUM
ZERO-ORDER
HOLD
f
S_IN
= 1/T1
f
S_OUT
= 1/T2
ORIGINAL SIGNAL
SAMPLED AT
f
S_IN
SIN(X)/X OF ZERO-ORDER HOLD
SPECTRUM OF ZERO-ORDER HOLD OUTPUT
OUT
IN
Figure 29. Zero-Order Hold Used by f
S_ OUT
to Resample Data from f
S_IN
Conceptual High Interpolation Model
g
y
to suppress the
s
th
Interpolation of the input data by a factor of 2
20
involves placin
(2
20
- 1) samples between each f
S_IN
sample. Figure 30 shows
both the time domain and the frequency domain of
interpolation by a factor of 2
20
. Conceptually, interpolation b
2
20
involves the steps of zero-stuffing (2
20
- 1) number of
samples between each f
S_IN
sample and convolving this
interpolated signal with a digital low-pass filter
images. In the time domain, it can be een at f
S_OUT
selects the
closest f
S_IN
2
20
sample from the zero-order hold, as opposed to
the nearest f
S_IN
sample in the case of no interpolation. This
significantly reduces the resampling error.
04577-0-010
f
S_IN
f
S_OUT
IN
OUT
INTERPOLATE
BY N
LOW-PASS
FILTER
ZERO-ORDER
HOLD
TIME DOMAIN OF
f
S_IN
SAMPLES
TIME DOMAIN OUTPUT OF THE LOW-PASS FILTER
TIME DOMAIN OF
f
S_OUT
RESAMPLING
TIME DOMAIN OF THE ZERO-ORDER HOLD OUTPUT
Figure 30. SRC Time Domain
In the frequency domain shown in Figure 31, the interpolation
expands the frequency axis of the zero-order hold. The images
from the interpolation can be su ficiently attenuated by a good
low-pass filter. The images from the zero-order hold are now
pushed by
n point
he
f
a factor of 2
20
closer to the infinite attenuatio
of the zero-order hold, which is f
S_IN
2
20
. The images at the
zero-order hold are the determining factor for the fidelity of t
output at f
S_OUT
.
04577-0-011
f
S_IN
f
S_IN
2
20
f
S_IN
2
20
f
S_IN
2
20
f
S_IN
f
S_OUT
IN
OUT
INTERPOLATE
BY N
LOW-PASS
FILTER
ZERO-ORDER
HOLD
FREQUENCY DOMAIN OF SAMPLES AT
f
S_IN
FREQUENCY DOMAIN OF THE INTERPOLATION
FREQUENCY DOMAIN OF
f
S_OUT
RESAMPLING
FREQUENCY DOMAIN
AFTER RESAMPLING
SIN(X)/X OF ZERO-ORDER HOLD
Figure 31. Frequency Domain of the Interpolation and Resampling
background image
ADAV801
Rev. 0 | Page 20 of 56
The
mputed from the zero-order
F/f
S_INTERP
)/( F/f
S_INTERP
)
Hardware Model
The output rate of the low-pass filter in Figure 30 is the
interpolation rate:
2
20
192,000 kHz = 201.3 GHz
Sampling at a rate of 201.3 GHz is clearly impractical, not to
mention the number of taps required to calculate each
interpolated sample. However, because interpolation by 2
20
involves zero-stuffing 2
20
-1 samples between each f
S_IN
sample,
most of the multiplies in the low-pass FIR filter are by zero. A
further reduction can be realized, because only one interpolated
sample is taken at the output at the f
S_OUT
rate, so only one
convolution needs to be performed per f
S_OUT
period instead of
2
20
convolutions. A 64-tap FIR filter for each f
S_OUT
sample is
sufficient to suppress the images caused by the interpolation.
One difficulty with the above approach is that the correct
interpolated sample must be selected upon the arrival of
UT
.
Because th
eriod, the
lyphase
26
,
e
aled. As the input sample rate rises over
the output sample rate, the antialiasing filter's cutoff frequency
y
's FIFO block adjusts the
left and right input samples and ores them for the FIR filter's
c
to the FIFO blo
l servo loop.
tion
aling
tal
worst-case images can be co
hold frequency response:
maximum image = sin (
where:
F is the frequency of the worst-case image that would be
2
20
f
S_IN
f
S_IN
/2.
f
S_INTERP
is f
S_IN
2
20
.
The following worst-case images would appear for f
S_IN
equal to
192 kHz:
Image at f
S_INTERP
- 96 kHz = -125.1 dB
Image at f
S_INTERP
+ 96 kHz = -125.1 dB
f
S_O
ere are 2
20
possible convolutions per f
S_OUT
p
arrival of the f
S_OUT
clock must be measured with an accuracy of
1/201.3 GHz = 4.96 ps. Measuring the f
S_OUT
period with a clock
of 201.3 GHz frequency is clearly impossible; instead, several
coarse measurements of the f
S_OUT
clock period are made and
averaged over time.
Another difficulty with the above approach is the number of
coefficients required. Because there are 2
20
possible convolu-
tions with a 64-tap FIR filter, there must be 2
20
po
coefficients for each tap, which requires a total of 2 coeffi-
cients. To reduce the number of coefficients in ROM, the SRC
stores a small subset of coefficients and performs a high order
interpolation between the stored coefficients.
The above approach works when f
S_OUT
> f
S_IN
. However, when
the output sample rate, f
S_OUT
, is less than the input sample rate
f
S_IN
, the ROM starting address, input data, and length of th
convolution must be sc
must be lowered, because the Nyquist frequency of the output
samples is less than the Nyquist frequency of the input samples.
To move the cutoff frequency of the antialiasing filter, the
coefficients are dynamically altered and the length of the
convolution is increased by a factor of (f
S_IN
/f
S_OUT
).
This technique is supported by the Fourier transform propert
that, if f(t) is F(), then f(k t) is F(/k). Thus, the range of
decimation is limited by the size of the RAM.
SRC Architecture
The architecture of the sample rate converter is shown in
Figure 32. The sample rate converter
st
onvolution cycle. The f
S_IN
counter provides the write address
ck and the ramp input to the digita
The ROM stores the coefficients for the FIR filter convolu
and performs a high order interpolation between the stored
coefficients. The sample rate ratio block measures the sample
rate for dynamically altering the ROM coefficients and sc
of the FIR filter length as well as the input data. The digi
servo loop automatically tracks the f
S_IN
and f
S_OUT
sample rates
and provides the RAM and ROM start addresses for the start of
the FIR filter convolution.
04577-0-012
RIGHT DATA IN
LEFT DATA IN
FIFO
ROM A
ROM B
DIGITAL
SERVO LOOP
f
S_IN
COUNTER
ROM C
ROM D
f
S_IN
f
S_OUT
SAMPLE RATE RATIO
SAMPLE
RATE RATIO
EXTERNAL
RATIO
INTERP
FIR FILTER
L/R DATA OUT
HIGH
ORDER
Figure 32. Architecture of the Sample Rate Converter
The FIFO receives the left and right input data and adjusts the
amplitude of the data for both the soft muting of the sample
rate converter and the scaling of the input data by the sample
rate ratio before storing the samples in the RAM. The input data
is scaled by the sample rate ratio, because, as the FIR filter
length of the convolution increases, so does the amplitude of the
convolution output. To keep the output of the FIR filter from
saturating, the input data is scaled down by multiplying it by
(f
S_OUT
/f
S_IN
) when f
S_OUT
< f
S_IN
. The FIFO also scales the input
data for muting and unmuting of the SRC.
The RAM in the FIFO is 512 words deep for both left and right
channels. An offset to the write address provided by the f
S_IN
counter is added to prevent the RAM read pointer from
overlapping the write address. The minimum offset on the SRC
is 16 samples. However, the group delay and mute-in register
can be used to increase this offset.
background image
ADAV801
Rev. 0 | Page 21 of 56
ut samples added to the write pointer of the
(512 - 16)/64 taps = 7.75
for short group delay and
(512 - 64)/64 taps = 7
for long group delay.
o of f
S_IN
/f
S_OUT
The number of inp
FIFO on the SRC is 16 plus Bit 6 to Bit 0 of the group delay
register. This feature is useful in varispeed applications to
prevent the read pointer to the FIFO from running ahead of the
write pointer. When set, Bit 7 of the group delay and mute-in
register soft-mutes the sample rate. Increasing the offset of the
write address pointer is useful for applications in which small
changes in the sample rate ratio between f
S_IN
and f
S_OUT
are
expected. The maximum decimation rate can be calculated
from the RAM word depth and the group delay as
The digital servo loop is essentially a ramp filter that provides
the initial pointer to the address in RAM and ROM for the start
of the FIR convolution. The RAM pointer is the integer output
of the ramp filter, and the ROM is the fractional part. The
digital servo loop must provide excellent rejection of jitter on
the f
S_IN
and f
S_OUT
clocks, as well as measure the arrival of the
f
S_OUT
clock within 4.97 ps. The digital servo loop also divides
the fractional part of the ramp output by the rati
to dynamically alter the ROM coefficients when f
S_IN
> f
S_OUT
.
04577-0-013
DIR P
LL (2
5
6
f
S
)
ICLK2
ICLK1
REG 0x00
BITS 10
REG 0x76
BIT 0
REG 0x76
BIT 1
REG 0x62
BITS 76
DIR P
LL (5
1
2
f
S
)
DIR
PLAYBACK
AUXILIARY IN
ADC
MCLKI
XIN
SRC
MCLK
SRC
OUTPUT
SRC
SRC
INPUT
PLLINT2
PLLINT1
Figure 33. Clock and Datapath Control on the SCR
The digital servo loop is implemented with a multirate filter. To
ttle the digital servo loop filter more quickly upon startup or a
added to the
ample rate is
easonable value, the digital
During fast mode, the MUTE_OUT bi
e error
e
he u
at clicks
ght
pres
l audio
tput of
e mu
Bit 7 of he group delay and
r
l t
ged to
he MU
an be
n inter
when the SRC
m
h
ing sample rate
onve
ly.
e
/f
S_IN
) 2
20
ratio for
se
change in the sample rate, a fast mode has been
filter. When the digital servo loop starts up or the s
changed, the digital servo loop enters fast mode to adjust and
settle on the new sample rate. Upon sensing that the digital
servo loop is settling down to a r
servo loop returns to normal (or slow) mode.
t in the sample rat
regist r is asserted to let t
ser know th
or pops mi
be
ent in the digita
data. The ou
the SRC can
b
ted by asserting
t
mute registe
unti he SRC has chan
slow mode. T
TE_OUT bit
c
set to generate a
rupt
changes to
slow
ode, indicating that t e data is be
c
rted accurate
The frequency responses of the digital servo loop for fast mod
and slow mode are shown in Figure 34. The FIR filter is a 64-tap
filter when f
S_OUT
f
S_IN
and is (f
S_IN
/f
S_OUT
) 64 taps when f
S_IN
>
f
S_OUT
. The FIR filter performs its convolution by loading in the
starting address of the RAM address pointer and the ROM
address pointer from the digital servo loop at the start of the
f
S_OUT
period. The FIR filter then steps through the RAM by
decrementing its address by 1 for each tap, and the ROM
pointer increments its address by the (f
S_OUT
f
S_IN
> f
S_OUT
or 2
20
for f
S_OUT
f
S_IN
. Once the ROM address rolls
over, the convolution is completed.
04577-0-014
FREQUENCY (Hz)
MAGNITUDE
(dB)
0
20
40
60
80
100
120
140
160
180
200
0.01
0.1
1
10
100
1k
10k
100k
SLOW MODE
FAST MODE
220
Figure 34. Frequency Response of the Digital Servo Loop. f
S_IN
is the X-Axis,
f
S_OUT
= 192 KHz, Master Clock is 30 MHz
The convolution is performed for both the left and right
channels, and the multiply accumulate circuit used for the
convolution is shared between the channels. The f
S_IN
/f
S_OUT
sample rate ratio circuit is used to dynam cally alter the
in the ROM when f
S_IN
> f
S_OUT
. The ratio is
calculated by comparing the output of an f
S_OUT
counter to the
output of an f
S_IN
counter. If f
S_OUT
> f
S_IN
, the ratio is held at one.
UT
, the sample rate ratio is updated, if it is different
by more than two f
S_OUT
periods from the previous f
S_OUT
to f
S_IN
comparison. This is done to provide some hysteresis to prevent
i
coefficients
If f
S_IN
> f
S_O
the filter length from oscillating and causing distortion.
background image
ADAV801
Rev. 0 | Page 22 of 56
an external
PLL SECTION
The ADAV801 features a dual PLL configuration to generate
independent system clocks for asynchronous operation.
Figure 37 shows the block diagram of the PLL section. The PLL
generates the internal and system clocks from a 27 MHz clock.
This clock is generated either by a crystal connected between
XIN and XOUT, as shown in Figure 35, or from
clock source connected directly to XIN. A 54 MHz clock can
also be used, if the internal clock divider is used.
C
C
XTA
04577-0-015
L
XIN
XOU
T
Figure 35. Crystal Connection
Both PLLs (PLL1 and PLL2) can be programmed independently
and can accommodate a range of sampling rates (32/44.1/48
kHz) with selectable system clock oversampling rates of 256 and
384. Higher oversampling rates can also be selected by enabling
the doubling of the sampling rate to give 512 or 768 f
S
ratios.
Note that this option also allows oversampling ratios of 256 or
384 at double sample r
z.
The PLL outputs can be routed internally to act as clock sources
for the oth
, and so
on. The outputs of the PLLs are also available on the three
SYSCLK pins. Figure 38 shows how the PLLs can be configured
to provide the sampling clocks.
MCLK Selection
ates of 64/88.2/96 kH
er component blocks such as the ADC, DAC
Table 7. PLL Frequency Selection Options
PLL
Sample Rate (f
S
)
Normal f
S
Double f
S
1
32/44.1/48 kHz
256/384 f
S
512/768 f
S
64/88.2/96 kHz
256/384 f
S
2A
32/44.1/48 kHz
256/384 f
S
512/768 f
S
64/88.2/96 kHz
256/384 f
S
2B
Same as f
S
selected
512 f
S
For PLL 2A
512 f
S
The PLLs require some external components to operate
correctly. These c
6, form a loop
p and
ty
ows
d as master clocks
r t
e ADAV801
e DAC or ADC.
e
nd gro
pins, which should be
l
t electri
se from being
nv
ouplin
ns.
omponents, shown in Figure 3
filter that integrates the current pulses from a charge pum
produces a voltage that is used to tune the VCO. Good quali
capacitors, such as PPS film, are recommended. Figure 37 sh
a block diagram of the PLL section, including master clock
selection. Figure 38 shows how the clock frequencies at the
clock output pins, SYSCLK1 to SYSCLK 3, and the internal PLL
clock values, PLL1 and PLL2, are selected.
The clock nodes, PLL1 and PLL2, can be use
fo he other blocks in th
such as th
Th PLL has separate supply a
und
as c ean as possible to preven
cal noi
co erted into clock jitter by c
g onto the loop filter pi
04577-0-016
PLL BLOCK
3.3k
PLL_LFx
100nF
AVDD
6.8nF
Figure 36. PLL Loop Filter
04577-0-017
MCLKI
REG 0x
BIT
MCLKO
REG 0x74
BIT 5
G 0x74
BIT 4
REG 0x78
BIT 6
78
7
PHASE
DETECTOR
AND LOOP
FILTER
PLL1
SYSCLK1
SYSCLK2
SYSCLK3
PLL_LF2
XOUT
RE
XIN
PLL_LF1
2
2
VCO
N
OUTPUT
SCALER N1
PHASE
DETECTOR
AND LOOP
FILTER
PLL2
VCO
N
OUTPUT
SCALER N2
OUTPUT
SCALER N3
Section Block Diagram
Figure 37. PLL
background image
ADAV801
Rev. 0 | Page 23 of 56
04577-0-018
PLL1 MCLK
PLL2 MCLK
48kHz
32kHz
44.1kHz
256
384
REG 0x75
BITS 32
REG
REG 0x75
BIT 1
0x75
BIT 0
REG 0x77
BIT 0
PLL1
PLLINT1
SYSCLK1
2
FS1
2
REG 0x75
BIT 5
REG 0x75
BIT 4
REG 0x77
BITS 21
x7
76
PLL2
PLLINT2
SYSCLK2
REG 0
BITS
5
REG 0x74
BIT 0
SYSCLK3
48kHz
32kHz
44.1kHz
256
384
2
FS2
FS3
2
2
256
512
Figure 38. PLL Clocking Scheme
SPDIF TRANSMITTER AND RECEIVER
The ADAV801 contains an integrated SPDIF transmitter and
receiver. The transmitter consists of a single output pin,
DITOUT, on which the biphase encoded data appears. The
SPDIF transmitter source can be selected from the different
blocks making up the ADAV801. Additionally, the clock source
for the SPDIF transmitter can be selected from the various clock
sources available in the ADAV801.
The receiver uses two pins, DIRIN and DIR_LF. DIRIN accepts
the SPDIF input data stream. The DIRIN pin can be configured
to accept a digital input level, as defined in the Specifications
section, or an input signal with a peak-to-peak level of 200 mV
minimum, as defined by the IEC60958-3 specification. DIR_LF
is a loop filter pin, required by the internal PLL, which is used to
recover the clock from the SPDIF data stream.
The components shown in Figure 42 form a loop filter, which
integrates the current pulses from a charge pump and produces
a voltage that is used to tune the VCO of the clock recovery
PLL. The recovered audio data and audio clock can be routed to
the different blocks of the ADAV801, as required. Figure 39
shows a conceptual diagram of the DIRIN block.
C*
04577-0-019
SPDIF
* EXTERNAL CAPACITOR IS REQUIRED ONLY
FOR VARIABLE LEVEL SPDIF INPUTS.
COMPARATOR
REG 0x74
BIT 4
DIRIN
DC
LEVEL
SPDIF
RECEIVER
Figure 39. DIRIN Block
04577-0-020
DIT
INPUT
DIT
PLAYBACK
AUXILIARY IN
SRC
REG 0x63
BITS 20
ADC
CHANNEL STATUS
AND USER BITS
DIR
DITOUT
Figure 40. Digital Output Transmitter Block Diagram
04577-0-021
DIR
DIRIN
AUDIO
DATA
RECOVERED
CLOCK
CHANNEL STATUS/
USER BITS
Figure 41. Digital Input Receiver Block Diagram
background image
ADAV801
Rev. 0 | Page 24 of 56
04577-0-022
DIR BLOCK
DIR_LF
100nF
3k
AVDD
6.8nF
Figure 42.
one
l Dig
udio
tand
ADAV801 can receive and tra
PDIF, AES/EBU
958 serial str
d,
/EBU is a profe
958 has
sumer and pro
ta sheet is
tended to f
e
rds. Con
e full specification
e digita
audio control info
e-mark
d. This encoding me
content of the
itted signal. As c
in the
al data end up with m
e biphase-
encoded data, while 0s in
ta do not. Note
e biphase-mark encod
a transition
en bit bounda
DIR Loop Filter Comp
nts
Seria
ital A
Transmission S
ards
The
nsmit S
, and
IEC-
eams. SPDIF is a consumer audio standar
and AES
ssional audio standard. IEC-
both con
fessional definitions. This da
not in
ully define or to provide a tutorial for thes
standa
tact the international standards-setting bodies
for th
s.
All thes
l audio communication schemes encode audio
data and
rmation using the biphas
metho
thod minimizes the dc
transm
an be seen from Figure 43, 1s
origin
idcell transitions in th
mark
the original da
that th
ed
s
data always ha
betwe
ries.
0
1
1
1
0
0
04577-0-023
CLOCK
(2 TIMES BIT RATE)
BIPHASE-MARK
DATA
DATA
Figure 43. Biphase-Mark Encoding
Digital audio-communication schemes use preambles to
distinguish among channels (called subframes) and among
longer-term control information blocks (called frames).
Preambles are particular biphase-mark patterns, which contain
encoding violations that allow the receiver to uniquely
recognize them. These patterns and their relationship to frames
and subframes are shown in Table 8 and Figure 44.
Table 8. Biphase-Mark Encode Preamble
Biphase Patterns
Channel
X
11100010 or 00011101
Left
Y
11100100 or 00011011
Right
Z
11101000 or 00010111
Left and CS block start
X
Y
Z
Y
X
Y
04577-
0
2
4
PREAMBLES
LEFT CH
FRAME 191
FRAME 0
FRAME 1
RIGHT CH
LEFT CH
RIGHT CH
LEFT CH
RIGHT CH
SUB-
FRAME
SUB-
FRAME
0-
Figure 44. Preambles, Frames, and Subframes
The biphase-mark encoding violations are shown in Figure 45.
Note that all three preambles include encoding violations.
Ordinarily, the biphase-mark en ding method results in a
polarity transition
co
between bit boundaries.
1
1
1
0
0
0
1
0
1
1
1
0
0
1
0
0
1
1
1
0
1
0
0
0
04577-0-025
PREAMBLE X
PREAMBLE Y
PREAMBLE Z
Figure 45. Preambles
The serial digital a
rganized
e
Bits
udio communication scheme is o
using a frame and subframe construction. There are two
subframes per frame (ordinarily the left and right channel).
Each subframe includes the appropriate 4-bit preamble, up to
24 bits of audio data, a validity (V) bit, a user (U) bit, a channel
status (C) bit, and an even parity (P) bit. The channel status bits
and the user bits accumulate over many frames to convey
control information. The channel status bits accumulate over a
192 frame period (called a channel status block). The user bits
accumulate over 1,176 frames when the interconnect is imple-
menting the so-called subcode scheme (EIAJ CP-2401). Th
organization of the channel status block, frames, and subframes
is shown in Table 9 and Table 10. Note that the ADAV801
supports the professional audio standard from a software
point of view only. The digital interface supports only
consumer mode.
Table 9. Consumer Audio Standard
Data
Address 7
6 5 4 3
2
1
0
N
Channel
Status
Emphasis
Copy-
Non-
Pro
Co
right
Audio
/
n
= 0
N + 1
Category Code
N + 2
Channel Number Source
Number
N + 3
Reserved
Clock
Accuracy
Sampling Frequency
N + 4
Reserved
Word Length
N + 5 to
(N + 23)
Reserved
N = 0x20 for receiver channel status buffer.
N = 0x38 for transmitter channel status buffer.
background image
ADAV801
Rev. 0 | Page 25 of 56
Data
Bits
Table 10. Professional Audio Standard
Address 7
6 5 4 3
2
1
0
N
Sample
Frequency
Lock Emphasis
Non-
Audio
Pro/
Con
= 1
N + 1
User Bit Management
Channel Mode
N + 2
Alignm
Level
Use of Auxiliary Mode
ent
Source Word Length
Sample Bits
N + 3
Channel Identification
N + 4
f
S
Scal-
ing
Reference
Signal
Sample Frequency (f
S
)
Reserved
Digital Audio
N + 5
Reserved
N + 6
Alphanumeric Channel Origin Data--First Character
N + 7
Alphanumeric Channel Origin Data
N + 8
Alphanumeric Channel Origin Data
N + 9
el Origin Data--Last Character
Alphanumeric Chann
N + 1
lp
ion Data--First Character
0
A hanumeric Channel Destinat
N + 11
Alphanumeric Channel Destination Data
N + 12
Alphanumeric Channel Destination Data
N + 1
Al
3
phanumeric Channel Destination Data--Last Character
N + 14
Local Sample Address Code--LSW
N + 15
Local Sample Address Code
N + 16
Local Sample Address Code
N + 17
Local Sample Address Code--MSW
N + 18
Time of Day Code--LSW
N + 19
Time of Day Code
N + 20
Time of Day Code
N + 21
Time of Day Code--MSW
N + 22
Reliability Flags
Reserved
N + 23
Cyclic Redundancy Check Character (CRCC)
N = 0x20 for receiver channel status buffer.
are
organized into 24 bytes and have the interpretations shown in
d
the need for user intervention.
Receiver Section
The ADAV801 uses a double-buffering scheme to handle read-
ing channel status and user bit information. The channel status
bits are available as a memory buffer, taking up 24 consecutive
register locations. The user bits are read using an indirect
memory addressing scheme, where the receiver user- bit
indirect-address register is programmed with an offset to the
iver user bit data register can be read
er
read
d
N = 0x38 for transmitter channel status buffer.
The standards allow the channel status bits in each subframe to
be independent, but ordinarily the channel status bit in the two
subframes of each frame are the same. The channel status bits
are defined differently for the consumer audio standards and
the professional audio standards. The 192 channel status bits
Table 9 and Table 10.
The SPDIF transmitter and receiver have a comprehensive
register set. The registers give the user full access to the
functions of the SPDIF block, such as detecting nonaudio an
validity bits, Q subcodes, preambles, and so on. The channel
status bits as defined by the IEC60958 and AES3 specifications
are stored in register buffers for ease of use. An autobuffering
function allows channel status bits and user bits read by the
receiver to be copied directly to the transmitter block, removing
user bit buffer, and the rece
to determine the user bits at that location. Reading the receiv
user bit data register automatically updates the indirect address
register to the next location in the buffer. Typically, the receiver
user bit indirect-address register is programmed to zero (the
start of the buffer), and the receiver user bit data register is
repeatedly until all the buffer's data has been read. Figure 46 an
Figure 47 show how receiving the channel status bits and user
bits is implemented.
04577-0-026
SECONDBUFFER
RECEIVE
CHANNEL
STATUS A
(24 8 BITS)
DIRIN
CS BUFFER
(0x200x37)
CHANNEL
STATUS B
(24 8 BITS)
RxCSSWITCH
SPDIF
RECEIVE
BUFFER
FIRST BUFFER
Figure 46. Channel Status Buffer
04577-0-027
BUFFER
SPDIFIN
0...7
8...15
16...23
FIRST
0...7
8...15
16...23
USER-BIT
BUFFER
ADDRESS = 0x50
ADDRESS = 0x51
RECEIVER USER BIT
INDIRECT ADDRESS
REGISTER
RECEIVER USER BIT
DATA REGISTER
Figure 47. Receiver User Bit Buffer
The SPDIF receive buffer is updated continuously by the
incoming SPDIF stream. Once all the channel status bits f
block (192 for Channel A and 192 for Channel B) are recei
or the
ved,
This
d the
bi n the channel status switch buffer register
in
eth
equi
to be
fer is
bytes
g and
Because the chan
change, a software
T, is provided to
tify th
ost co
tatus
bits is available or
status
formation have changed from a previous block. The function
of the RxCSBINT is controlled by the RxBCONF3 bit in the
receiver buffer configuration register.
The size of the user bit buffer can be set by programming the
RxBCONF0 bit in the receiver buffer configuration register, as
shown in Table 11.
the bits are copied into the receiver channel status buffer.
buffer stores all 384 bits of channel status information, an
RxCSSWITCH
t i
determ es wh
er the Channel A or the Channel B status bits
are r
red
read. The receive channel status bit buf
24
lon
spans the address range from 0x20 to 0x37.
nel status bits of an SPDIF stream rarely
interrupt/flag bit, RxCSBIN
no
e h
ntrol that either a new block of channel s
that the first five bytes of channel
in
background image
ADAV801
Rev. 0 | Page 26 of 56
er Bit Buffer Size
Table 11. RxBCONF3 Functionality
RxBCONF0
Receiver Us
0
384 bits with Preamble Z as the start of the block.
1
768 bits with Preamble Z as the start of the block.
The updating of the user bit buffer is controlled by Bits
RxBCONF21 and Bit 7 to Bit 4 of the channel status register, as
shown in Table 12 and Table 13.
Table 12. RxBCONF21 Functionality
RxBCONF
Bit 2
Bit 1
Receiver User Bit Buffer Configuration
0
0
User bits are ignored.
0
1
Update second buffer when first buffer is full.
1 0 Format according to Byte 1, Bit 4 to Bit 7, if
PRO bit is set. Format according to
IEC60958-3, if PRO bit is clear.

Table 13. Automatic User Bit Configuration
Bits
7 6 5 4
Automatic Receiver User Bit Buffer
Configuration
0 0 0 0 User
bits
are
ignored.
0 1 0 0 AES-18 format: the user bit buffer is treated in
the same way as when RxBCONF21 = 0b01.
1 0 0 0 User bit buffer is updated in the same way as
when RxBCONF21 = 0b01 and RxBCONF0 =
0b00.
1 1 0 0 User-defined format: the user bit buffer is
treated in the same way as when RxBCONF21
= 0b01.
When the user bit buffer has been filled, the RxUBINT
interrupt bit in the interrupt status register is set, provided that
the RxUBINT mask bit is set, to indicate that the buffer has new
information and can
se when the user data is formatted according
e and the
ed in
,
e
nel status buffer occupies
ts
ing
r into the SPDIF transmitter buffer until
finished loading the buffers. This feature is typically
e
be read.
For the special ca
to the IEC60958-3 standard into messages made of information
units, called IUs, the zeros stuffed between each IU and each
message are removed and only the IUs are stored. Once the end
of the message is sensed by more that eight zeros between IUs,
the user bit buffer is updated with the complete messag
first buffer begins looking for the start of the next message.
Each IU is stored as a byte consisting of 1, Q, R, S, T, U, V, and W
bits (see the IEC60958-3 specification for more information).
When 96 IUs are received, the Q subcode of the IUs is stor
the Q subcode buffer, consisting of 10 bytes. The Q subcode is
the Q bits taken from each of the 96 IUs. The first 10 bytes
(80 bits) of the Q subcode contain information sent by CD, MD
and DAT systems. The last 16 bits of the Q subcode are used to
perform a CRC check of the Q subcode. If an error occurs in
the CRC check of the Q subcode, the QCRCERROR bit is set.
This is a sticky bit that remains high until the register is read.
Transmitter Operation
The SPDIF transmitter has a similar buffer structure to th
receive section. The transmitter chan
24 bytes of the register map. This buffer is long enough to store
the 192 bits required for one channel of channel status informa-
tion. Setting the TxCSSWITCH bit determines if the data
loaded to the transmitter channel status buffer is intended for
Channel A or Channel B. In most cases, the channel status bi
for Channel A and Channel B are the same, in which case
setting the Tx_A/B_Same bit reads the data from the trans-
mitter channel status buffer and transmits it on both channels.
Because the channel status information is rarely changed dur
transmission, the information contained in the buffer is
transmitted repeatedly. The Disable_Tx_Copy bit can be used to
prevent the channel status bits from being copied from the
transmitter CS buffe
the user has
used, if the Channel A data and Channel B data are different.
Setting the bit prevents the data from being copied. Clearing th
bit allows the data to be copied and then transmitted. Figure 48
shows how the buffers are organized.
04577-0-028
TxCSSWITCH
TRANSMIT
CS BUFFER
(0x380x4F)
CHANNEL
STATUS A
(24 8 BITS)
CHANNEL
STATUS B
(24 8 BITS)
DITOUT
SPDIF
TRANSMIT
BUFFER
Figure 48. Transmitter Channel Status Buffer
As with the receiver section, the transmitted user bits are als
double-buffered. This is required, be
o
cause, unlike the channel
e
out alignment to the Z preamble. If
itting until a
bits are 01.
ble 14. Tr
urations
BCONF2-1
status bits, the user bits do not necessarily repeat themselves.
The user bits can be buffered in various configurations, as listed
in Table 14. Transmission of the user bits is determined by th
state of the BCONF3 bit. If the bit is 0, the user bits begin
transmitting right away with
this bit is 1, the user bits do not start transm
Z preamble occurs when the TxBCONF21
Ta
ansmitter User Bit Buffer Config
Tx
Bit 2
Bit 1
Transmitter User Bit Buffer Configuration
0
0
Zeros are transmitted for the user bits.
0
1
Host writes user bits to the buffer until it is full.
1 0 Writes the user bits to the buffer in IUs
specified by IEC60958-3 and transmits them
according to the standard.
1 1 First 10 bytes of the user-bit buffer are
configured to store a Q subcode.
background image
ADAV801
Rev. 0 | Page 27 of 56
Table 15. Transmitter User Bit Buffer Size
TxBCONF0 Buffer
Size
0
384 bits with Preamble Z as the start of the block.
1
768 bits with Preamble Z as the start of the block.
By using sticky bits and interrupts, the transmit buffers can
notify the host or microcontroller when the first user bit buffer
has been updated and when the second transmit user bit buffer
is full. The sticky bit, TxUBINT, is set when the transmit user bit
buffer has been updated and the second transmit user bit buffer
is ready to accept new user bits. The sticky bit, TxFBINT, is set
whenever the second transmit user bit buffer is full. Any new
writes to this buffer are ignored until the first transmit buffer is
updated. These two bits are located in the interrupt status
register. When the host reads the interrupt status register, these
bits are cleared. Interrupts for the TxUBINT and TxFBINT
sticky bits can be enabled by setting the TxUBMASK and
TxFBMASK bits, respectively, in the interrupt status
mask register.
04577-0-029
SPDIF 0
0...7
8...15
16...23
SECOND
BUFFER
0...7
8...15
16...23
USER-BIT
BUFFER
ADDRESS = 0x52
ADDRESS = 0x53
TRANSMITTER USER BIT
INDIRECT ADDRESS
REGISTER
TRANSMITTER USER BIT
DATA REGISTER
Figure 49. Transmitter User Bit Buffer
Autobuffering
The ADAV801 SPDIF receiver and transmitter sections have an
autobuffering mode allowing the channel status and user bits to
be copied automatically from the receiver to the transmitter
without user intervention. The channel status and user bits can
be independently selected for autobuffering using the
Auto_CSBits and Auto_UBits bits, respectively, in the autobuffer
register. When the receiver and transmitter are running at the
same sample rate, the transmitted channel status and user bits
are the same as the received channel-status and user bits.
In many systems, however, it is likely that the receiver and
transmitter are not running at the same frequency. When the
transmitter sample rate is higher than receiver sample rate, the
channel status and user bit block is sometimes repeated.
the transmitter sample rate is lower than the receiver sample
te, the channel status and user bit blocks might be dropped.
ecause the first five bytes of the channel status are typically
constant, they can be repeated or dropped with no information
loss. However, if the PRO bit in the channel status is set and the
local sample address code and time-of-day code bytes contain
958-3
sent
or repeating messages. Because zero-stuffing
s
essages to be subtracted, the zeros
racted as well. The Zero_Stuff_IU bit in the
y.
rupt.
ach interrupt in the interrupt status register has an associated
mask bit in the interrupt status mask register. The interrupt
mask bit must be set for the corresponding interrupt to be
generated. This feature allows the user to determine which
functions should be responded to.
The dual function pin ZEROL/INT can be set to indicate the
presence of no audio data on the left channel or the presence of
an interrupt set in the interrupt status register. As shown in
Table 16, the function of this pin is selected by the INTRPT bit
in DAC Control Register 4.
Table 16. ZEROL/INT Pin Functionality
INTRPT Pin
Functionality
When
ra
B
information, these bytes might be repeated or dropped, in
which case information can be lost. It is up to the user to
determine how to handle this case.
When the user bits are transmitted according to the IEC60
format, the messages contained in the user bits can still be
without dropping
is allowed between IUs and messages, zeros can be added or
subtracted to preserve the messages. When the transmitter
sample rate is greater than the receiver sample rate, extra zeros
are stuffed between the messages. When the sample rate of the
transmitter is less than the sample rate of the receiver, the zero
stuffed between the messages are subtracted. If there are not
en the m
enough zeros betwe
between IUs are subt
autobuffer register enables the adding or subtracting of zeros
between messages.
Interrupts
The ADAV801 provides interrupt bits to indicate the presence
of certain conditions that require attention. Reading the
interrupt status register allows the user to determine if any of
the interrupts have been asserted. The bits of the interrupt
status register remain high, if set, until the register is read. Two
bits, SRCError and RxError, indicate interrupt conditions in the
sample rate converter and an SPDIF receiver error, respectivel
Both these conditions require a read of the appropriate error
register to determine the exact cause of the inter
E
0
Pin functions as a ZEROL flag pin.
1
Pin functions as an interrupt pin.
SERIAL DATA PORTS
The ADAV801 contains four flexible serial ports (SPORTs) to
ta transfer to and from the codec. All four SPORTs are
independent and can be configured as master or slave ports. In
slave mode, the xLRCLK and xBCLK signals are inputs to the
serial ports. In master mode, the serial port generates the
xLRCLK and xBCLK signals. The master clock for the SPORT
can be selected from a number of sources, as shown in
Figure 50.
allow da
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ADAV801
Rev. 0 | Page 28 of 56
04577-0-031
REG 0x76
BITS 42
DIR PLL (512
f
S
)
DIR PLL (256
f
S
)
PLLINT1
PLLINT2
MCLKI
XIN
ICLK1
ICLK2
PLL CLOCK
REG 0x06
BITS 43
MCLK
ADC
OUTPUT
PORT
OLRCLK
LK
OBC
OSDATA
REG 0x76
BITS 75
DIR PLL (512
f
S
)
DIR PLL (256
f
S
)
PLLINT1
PLLINT2
MCLKI
XIN
ICLK1
ICLK2
PLL CLOCK
REG 0x04
BITS 4-3
MCLK
DAC
INPUT
PORT
ILRCLK
IBCLK
ISDATA
REG 0x77
BITS 43
REG 0x00
BITS 32
REG 0x00
BITS 10
REG 0x00
BITS 45
REG 0x76
BITS 10
MCLKI
XIN
PLLINT1
PLLINT2
ICLK1
ICLK2
DIR PLL (512
f
S
)
DIR PLL (256
f
S
)
REG 0x00
BITS 1-0
MCLKI
XIN
PLLINT1
PLLINT2
DIVIDER
DIVIDER
DIVIDER
SRC
MCLK
Figure 50. SPORT Clocking Scheme
le,
MCLKI input to ensure that the
C and serial port are
synchronized.
The SPORTs can be set
ive data in I
2
S, left-
justified or right-justified formats with different word lengths
by programming the appropriate bits in the playback register,
auxiliary input port register, record register, and auxiliary
output port-control register. Figure 51 is a timing diagram of
the serial data port formats.
Clocking Scheme
The ADAV801 provides a flexible choice of on-chip and off-
chip clocking sources. The on-chip oscillator with dual PLLs is
intended to offer complete system clocking requirements for
use with available MPEG encoders, decoders, or a combination
of codecs. The oscillator function is designed for generation of a
27 MHz video clock from a 27 MHz crystal connected between
the XIN and XOUT pins. Capacitors must also be connected
between these pins and DGND, as shown in Figure 35. The
capacitor values should be specified by the crystal manufacturer.
A square wave version of the crystal clock is output on the
MCLKO pin. If the system has a 27 MHz clock available, this
clock can be connected directly to the XIN pin.
Care should be taken to ensure that the clock rate is appropriate
for whatever block is connected to the serial port. For examp
if the ADC is running from the MCLKI input at 256 f
S
, then
the master clock for the SPORT should also run from the
AD
to transmit or rece
04577-0-030
LRCLK
BCLK
SDATA
LRCLK
BCLK
SDATA
LRCLK
BCLK
SDATA
LSB
LSB
LSB
LSB
LSB
LSB
LEFT CHANNEL
RIGHT CHANNEL
RIGHT CHANNEL
LEFT CHANNEL
LEFT CHANNEL
RIGHT CHANNEL
MSB
MSB
MSB
MSB
MSB
MSB
RIGHT-JUSTIFIED MODE -- SELECT NUMBER OF BITS PER CHANNEL
I
2
S MODE -- 16 BITS TO 24 BITS PER CHANNEL
LEFT-JUSTIFIED MODE -- 16 BITS TO 24 BITS PER CHANNEL
Figure 51. Serial Data Modes
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ADAV801
Rev. 0 | Page 29 of 56
put/output switching/
le
s include the
output ports (both 3-wire digital) and the
.
Datapath
The ADAV801 features a digital in
multiplexing matrix that gives flexibility to the range of possib
input and output connections. Digital input ports include
playback and auxiliary input (both 3-wire digital), and S/PDIF
(single-wire to the on-chip receiver). Output port
record and auxiliary
S/PDIF port (single-wire from the on-chip transmitter).
Internally, the DIR and DIT are interfaced via 3-wire interfaces
The datapath for each input and output port is selected by
programming Datapath Control Registers 1 and 2. Figure 52
shows the internal datapath structure of the ADAV801.
04577-0-032
PLL
ADC
DAC
OSCILLATOR
REFERENCE
AUX
DATA
OUTPUT
DIT
SRC
CONTROL
REGISTERS
PLAYBACK
DATA
INPUT
DIR
AUX
DATA
INPUT
RECORD
DATA
OUTPUT
Figure 52. Datapath
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ADAV801
Rev. 0 | Page 30 of 56
ADAV801 has a d
cated contro
ort to allow access to
AV801. Each of the internal
ght bits w
s reserved
these bits shoul
ACE
ontrol of the ADAV8
.
l port is
ycle of data transfer c
s. Figure 53 shows the
rmat of an SPI write
The transfer of
ata is initiated on the
ATCH. The data
resented on the first s
ents the register
rite bit.
f data are loaded to th
provided. If this bit is
h, a read operation is indicated. The contents of the register
ess are clocked ou
n on the following eight
CLKs. For a read ope
ts after the read/write
BLOCK EADS AN
The ADAV801 provides the user with the ability to write to or
read from a block of registers in one continuous operation. In
SPI mode, the CLATCH line should be held low for longer than
the 16 CCLK periods to use the block read/write mode. For a
write operation, once the LSB has been clocked into the
ADAV801 on the 16th CCLK, the register address as specified
by the first seven bits of the write operation is incremented and
the next eight bits are clocked into the next register address.
The read operation is similar. Once the LSB of a read register
operation has been clocked out, the register address is
incremented and the data from the next register is clocked out
on the following eight CCLKs. Figure 55 and Figure 56 show the
timing diagrams for the block write and read operations.
INTERFACE CONTROL
The
edi
l p
the internal registers of the AD
registers is ei
ide. Where bits are described a
(RES),
d be programmed as zero.
SPI INTERF
C
01 is via an SPI-compatible serial port
The SPI contro
a 4-wire serial control port with one
c
onsisting of 16 bit
fo
/read of the ADAV801.
d
falling edge of CL
p
even CCLKs repres
address read/w
If this bit is low, the following eight bits
o
e register address
hig
addr
t on the COUT pi
C
ration, the data bi
bits are ignored.
R
D WRITES
CLATCH
CCLK
CIN
D0
D8
D0
D14
D9
D8
COUT
D15
D9
04577-0-033
SPI Serial Port Timing Diagram
Figure 53.
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
R/W
15
ADDRESS [6:0]
DATA [7:0]
04577-0-036
re 54. SPI C
orm
REGISTER DATA
REGISTER + 1 DATA
REGISTER + 2 DATA
Figu
ontrol Word F
at
04577-0-034
REGISTER
R/W = 0
8 BITS
CLATCH
CIN
8 BITS
8 BITS
8 BITS
Figure 55. SPI Block Write Operation
REGISTER DATA
REGISTER + 1 DATA
REGISTER + 2 DATA
04577-0-035
REGISTER
R/W = 1
8 BITS
8 BITS
8 BITS
8 BITS
CLATCH
CIN
DON'T CARE
C
Figure 56. SPI Block Read Operation
OUT
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ADAV801
Rev. 0 | Page 31 of 56
r
IV1
IV0
DIV1
Table 17. SRC and Clock Control Registe
SRCD
SRCD
CLK2
CLK2DIV0
CLK1DIV1
CLK1DIV0 MCLKSEL1 MCLKSEL0
7 6 5 4 3 2 1 0
ADDRESS = 0000000 (0x00)
SRCDIV10
Divides the SRC master clock.
00 = SRC master clock is not divided.
vided by 1.5.
is divided by 2.
is divided by 3.
e by 1.5.
ck 1 (ICLK1).
01 = Divide by 1.5.
10 = Divide by 2.
selection
e SRC m
= Internal C
k 1.
ernal Clock 2.
6 f
S
).
01 = SRC master clock is di
10 = SRC master clock
11= SRC master clock
CLK2DIV10
Clock divider for Internal Clock 2 (ICLK2).
00 = Divide by 1.
01 = Divid
10 = Divide by 2.
11 = Divide by 3.
CLK1DIV10
Clock divider for Internal Clo
00 = Divide by 1.


11 = Divide by 3.
MCLKSEL10
Clock
for th
aster clock.
00
loc
01 = Int
10 = PLL recovered clock (512 f
S
).
11 = PLL recovered clock (25

Table 18. SPDIF Loop
RES RES RES RES RES TxMUX
back Control Register
RES RES
7 6 5 4 3 2 1 0
ADDRESS = 0000011 (0x03)
TxMUX
Selects the source for SPDIF output (DITOUT).
0 = SPDIF transmitter, normal mode.
1 = DIRIN, loopback mode.
Table 19. Playback Port Control Register
CLKSRC0
SPMODE2
SPMODE1
SPMODE0
RES RES RES CLKSRC1
7 6 5 4 3 2 1 0
ADDRESS = 0000100 (0x04)
CLKSRC10
Selects the clock source for generating the ILRCLK and IBCLK.
00 = Input port is a slave.
01 = Recovered PLL clock.
10 = Internal Clock 1.
11 = Internal Clock 2.
SPMODE20
Selects the serial format of the playback port.
000 = Left-justified.
001 = I
2
S.
100 = 24-bit, right-justified.
101 = 20-bit, right-justified.
110 = 18-bit, right-justified.
111 = 16-bit, right-justified.
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ADAV801
Rev. 0 | Page 32 of 56
2
Table 20. Auxiliary Input Port Register
RES RES RES CLKSRC1
CLKSRC0
SPMODE
SPMODE1
SPMODE0
7 6 5 4 3 2 1 0
ADDRESS = 0000101 (0x05)
CLKSRC10
Selects the clock source for generating the IAUXLRCLK and IAUXBCLK.
00 = Input port is a slave.
01 = Recovered PLL cock.
10 = Internal Clock 1.
11 = Internal Clock 2.
SPMODE20
ut port.
tified.
right-justified.
right-justified.
ustified.
Selects the serial format of auxiliary inp
000 = Left-jus
001 = I
2
S.
100 = 24-bit,
101 = 20-bit,
110 = 18-bit, right-justified.
111 = 16-bit, right-j
Table 21. Record Por
RES
RES
CLKSRC1
CLKSRC0
WLEN1 WLEN0 SPMODE1
SPMODE0
t Control Register
7 6 5 4 3 2 1 0
ADDRESS = 0000110 (0x06)
CLKSRC10
Selects the clock source for gen
RCLK and OBCLK.
erating the OL
00 = Record port is a slave.
covered PLL clock.
lock 2.
l output word length.
record port.
01 = I
2
S.
10 = Reserved.
11 = Right-justified.
01 = Re
10 = Internal Clock 1.
11 = Internal C
WLEN10
Selects the seria
00 = 24 bits.
01 = 20 bits.
10 = 18 bits.
11 = 16 bits.
SPMODE10
Selects the serial format of the
00 = Left-justified.
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ADAV801
Rev. 0 | Page 33 of 56
RES
C1
CL
1
0 SPMO
MODE0
Table 22. Auxiliary Output Port Register
RES
CLKSR
KSRC0
WLEN
WLEN
DE1
SP
7 6 5 4 3 2 1 0
ADDRESS = 0000111 (0x07)
CLKSRC10
CLK.
Selects the clock source for generating the OAUXLRCLK and OAUXB
00 = Auxiliary record port is a slave.
01 = Recovered PLL clock.
ecord port.
10 = Internal Clock 1.
11 = Internal Clock 2.
WLEN10
Selects the serial output word length.
00 = 24 bits.
01 = 20 bits.
10 = 18 bits.
11 = 16 bits.
SPMODE10
Selects the serial format of the auxiliary r
00 = Left-justified.
01 = I
2
S.
10 = Reserved.
11 = Right-justified.
Table 23. Group Dela
GRPDLY60
y and Mute Register
MUTE_SRC
7
6, 5, 4, 3, 2, 1, 0
ADDRESS = 0001000
(0x08)
MUTE_SRC
Soft-mutes the output of the sample rate converter.
0 = No mute.

y to the sample rate converter FIR filter by GRPDLY60 inpu
ples.
00000 = No de
.
1 = 1 sample delay.



1 = Soft-mute.
GRPDLY60
Adds dela
t sam
00
lay
000000
0000010 = 2 sample delay.
1111110 = 126 sample delay.
1111111 = 127 sample delay.
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ADAV801
Rev. 0 | Page 34 of 56
OCK RxCLK1
AU
Table 24. Receiver Configuration 1 Register
NOCL
0
TO_
DEEMPH
ERR10
LOCK10
7
6, 5
4
3, 2
1, 0
ADDRESS = 0001001 (0x09)
NOCLOCK
Selects the source of the receiver clock when the PLL is not locked.
clock.
PH
ata from the receiver based on the channel status information.
should take, if the receiver detects a parity or biphase error.



OCK10
tion the receiver should take, if the PLL loses lock.
11 = Soft-mute of the last valid audio sample.
0 = Recovered PLL clock is used.
1 = ICLK1 is used.
RxCLK10
Determines the oversampling ratio of the recovered receiver clock.
00 = RxCLK is a 128 f
S
recovered clock.
01 = RxCLK is a 256 f
S
recovered clock.
10 = RxCLK is a 512 f
S
recovered
11 = Reserved.
AUTO_DEEM
Automatically de-emphasizes the d
0 = Automatic de-emphasis is disabled.
1 = Automatic de-emphasis is enabled.
ERR10
Defines what action the receiver
00 = No action is taken.
01 = Last valid sample is held.
10 = Invalid sample is replaced with zeros.
11 = Reserved.
L
Defines what ac
00 = No action is taken.
01 = Last valid sample is held.
10 = Zeros are sent out after the last valid sample.
Table 25. Receiver Co
ration 2 Register
SP_PL
SP_PLL_
SEL
RES RES NO
NONAUDIO
NO_VALIDITY
nfigu
RxMUTE
L 10
7
6
5,
4
3 2 1
0
ADDRESS = 0001010 (0x0A)
RxMUTE
Hard-mutes the audio output for the AES3/SPDIF receiver.
0 = AES3/SPDIF receiver is not muted.
1 = AES3/SPDIF receiver is muted.
SP_PLL
AES3/SPDIF receiver PLL accepts a left/right clock from one of the four serial ports as the PLL reference clock.
ES3/SPDIF preambles is the reference clock to the PLL.
ports is the reference clock to the PLL.
reference clock to the PLL when SP_PLL is set.
NONAUDIO
er is not allowed into the sample rate converter
efined by the IEC61937 standard, then the data from
receiver is not allowed into the SRC regardless of the state of this bit.
the SRC.
s not allowed into the SRC, if the NONAUDIO bit is set.
the AES3/SPDIF receiver is not allowed into the SRC.
0 = AES3/SPDIF receiver data is sent to the SRC.
1 = Data from the AES3/SPDIF receiver is not allowed into the SRC, if the VALIDITY bit is set.
0 = Left/right clock generated from the A
1 = Left/right clock from one of the serial
SP_PLL_SEL10
Selects one of the four serial ports as the
00 = Playback port is selected.
01 = Auxiliary input port is selected.
10 = Record port is selected.
11 = Auxiliary output port is selected.
NO
When the NONAUDIO bit is set, data from the AES3/SPDIF receiv
NAUDIO data is due to DTS, AAC, and so on, as d
(SRC). If the NO
the AES3/SPDIF
0 = AES3/SPDIF receiver data is sent to
1 = Data from the AES3/SPDIF receiver i

NO_VALIDITY
When the VALIDITY bit is set, data from
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ADAV801
Rev. 0 | Page 35 of 56
RES F5
RxBCONF4
NF3 RxB
RxBCONF0
Table 26. Receiver Buffer Configuration Register
RES
RxBCON
RxBCO
CONF21
7 6 5 4 3 2,
1
0
ADDRESS = 0001011 (0x0B)
RxBCONF5
If the user bits are formatted according to the IEC60958-3 standard and the DAT category is detected, the user bit
enabled only when there is a change in the start (ID) bit.
interrupt is
0 = User bit interrupt is enabled in normal mode.
If the DAT category is detected, the user bit interrupt is enabled only if there is a change in the start (ID) bit.
termines whether Channel A and Channel B user bits are stored in the buffer together or separated
and B.
eceiver channel status is read, which is 192 audio frames.
of the receiver channel status block changes from the previous channel
IEC60958-3 standard.
xBCONF0
Defines the user bit buffer size, if RxBCONF21 = 01.
rt of the buffer.
a
1 =
RxBCONF4
This bit de
between A
0 = User bits are stored together.
1 = User bits are stored separately.
RxBCONF3
Defines the function of RxCSBINT.
0 = RxCSBINT are set when a new block of r
1 = RxCSBINT is set only if the first five bytes
status block.
RxBCONF21
Defines the user bit buffer.
e ignored.
00 = User bits ar

01 = Updates the second user bit buffer when the first user bit buffer is full.
10 = Formats the received user bits according to Byte 1, Bit 4 to Bit 7, of the channel status, if the PRO bit is set. If the
PRO bit is not set, formats the user bits according to the
11 = Reserved.
R
0 = 384 bits with Preamble Z as the sta
8 b
h Pr
st
1 = 76
its wit
eamble Z as the
rt of the buffer.
Table 27. Transmitter Control Register
RES
TxVALIDITY
TxRATIO20
TxCLKSEL10
TxENABLE
7
6
5, 4, 3
2, 1
0
ADDRESS = 0001100 (0x0C)
TxVALIDITY
This bit is used to set or clear the VALIDITY bit in the AES3/SPDIF transmit stream.
0 = Audio is suitable for D/A conversion.
1 = Audio is not suitable for D/A conversion.
TxRATIO20
Determines the AES3/SPDIF transmitter to AES3/SPDIF receiver ratio.
00 = Internal Clock 1 is the cl
01 = Internal Clock 2 is the clock source for the transmitter.
ce for the transmitter.
3/SPDIF transmitter is disabled.
000 = Transmitter to receiver ratio is 1:1.
001 = Transmitter to receiver ratio is 1:2.
010 = Transmitter to receiver ratio is 1:4.
101 = Transmitter to receiver ratio is 2:1.
110 = Transmitter to receiver ratio is 4:1.
TxCLKSEL10
Selects the clock source for the AES3/SPDIF transmitter.
ock source for the transmitter.

10 = Recovered PLL clock is the clock sour
11 = Reserved.
TxENABLE
Enables the AES3/SPDIF transmitter.
0 = AES
1 = AES3/SPDIF transmitter is enabled.
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ADAV801
Rev. 0 | Page 36 of 56
TxBCONF3
TxBCONF21 TxBCONF0
Table 28. Transmitter Buffer Configuration Register
IU_Zeros30
7, 6, 5, 4
3
2, 1
0
ADDRESS = 0001101 (0x0D)
IU_Zeros30
Determines the number of zeros to be stuffed between IUs in a message up to a maximum of 8.
0000 = 0.
11 = 7.
8.
ser bits.
size is configured according to TxBCONF0.
ter user bits when TxBCONF21 is 01.
s with Preamble Z as the start of the buffer.
0001 = 1.
...
01
1000 =
TxBCONF3
Transmitter user bits can be stored in separate buffers or stored together.
0 = User bits are stored together.
1 = User bits are stored separately.
TxBCONF21
Configures the transmitter user bit buffer.
00 = Zeros are transmitted for the u
01 = Transmitter user bit buffer
10 = User bits are written to the transmit buffer in IUs specified by the IEC60958-3 standard.
11 = Reserved.
TxBCONF0
Determines the buffer size of the transmit
0 = 384 bits with Preamble Z as the start of the buffer.
1 = 768 bit
Table 29. Channel Status Switch Buffer and Transmitter
Disable_Tx_Copy
RES RES TxCSSWITCH RxCSSWITCH
RES RES Tx_A/B_Same
7 6 5
4
3 2 1
0
ADDRESS = 0001110 (0x0E)
Tx_A/B_Same
Transmitter Channel Status A and B are the same. The transmitter reads only from the Channel Status A buffer and
s the data into t
place
he Channel Status B buffer.
0 = Channel status for A and B are separate.
nnel status for A and B are the same.
nsmitter channel status buffer to the SPDIF transmitter
0 = Copying transmitter channel status is enabled.
tus is disabled.
channel status buffer.
itter Channel Status A buffer can be accessed at address locations 0x38 through 0x4F.
yte Transmitter Channel Status B buffer can be accessed at address locations 0x38 through 0x4F.
0 = 24-byte Receiver Channel Status A buffer can be accessed at address locations 0x20 through 0x37.
1 = 24-byte Receiver Channel Status B buffer can be accessed at address locations 0x20 through 0x37.
1 = Cha
Disable_Tx_Copy
Disables the copying of the channel status bits from the tra
buffer.

1 = Copying transmitter channel sta
TxCSSWITCH
Toggle switch for the transmit
0 = 24-byte Transm
1 = 24-b
RxCSSWITCH
Toggle switch for the receive channel status buffer.
Table 30. Transmitte
t Significant Byte
r Message Zeros M
ros70
os
MSBZe
7, 6, 5, 4, 3, 2, 1, 0
ADDRESS = 0001111 (0x0F)
MSBZeros70
Most significant byte of the number of zeros to be stuffed between IEC60958-3 messages (packets).
Default = 0x00.
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ADAV801
Rev. 0 | Page 37 of 56
icant Byte
Table 31. Transmitter Message Zeros Least Signif
LSBZeros70
7, 6, 5, 4, 3, 2, 1, 0
ADDRESS = 0010000 (0x10)
LSBZeros70
Least significant byte of the number of zeros to be stuffed between IEC60958-3 messages (packets). Default = 0x09.
able 32. Autobuffer Register
Stuff_IU
Auto_UBits
Auto_CSBits
IU_Zeros30
T
RES
Zero_
7 6 5 4 3,
2,
1,
0
ADDRESS = 0010001 (0x11)
Zero_Stuff_IU
Enables the addition or subtraction of zeros between IUs during autobuffering of the user bits in IEC60958-3 format.

0 = No zeros added or subtracted.
1 = Zeros can be added or subtracted between IUs.
Enables the user bits to be autobuffered
Auto_UBits
between the AES3/SPDIF receiver and transmitter.
0 = User bits are not autobuffered.
1 = User bits are autobuffered.
ts to be autobuffered between the AES3/SPDIF receiver and transmitter.
s are not autobuffered.
bits are autobuffered.
maximum number of zero-stuffing to be added between IUs while autobuffering up to a maximum of 8.

0111 = 7.


Auto_CSBits
Enables the channel status bi
0 = Channel status bit
1 = Channel status
IU_Zeros30
Sets the
0000 = 0.
0001 = 1.
...

1000 = 8.
33. Sample Rat
R
ad
SRCRATIO14SRCRATIO08
Table
e Ratio MSB egister (Re
Only)
RES
7
6, 5, 4, 3, 2, 1, 0
ADDRESS = 0010010 (0x12)
SRCRATIO1408
Seven most significant bits of the15-bit sample rate ratio.
Table 34. Sam
ple Rate Ratio LSB Register (Read Only)
SRCRATIO07SRCRATIO00
7, 6, 5, 4, 3, 2, 1, 0
ADDRESS = 0010011 (0x13)
SRCRATIO0700
Eight least significant bits of the15-bit sample rate ratio.
Table 35. Preamble-C
PRE_C15PRE_C08
MSB Register (Read Only)
7, 6, 5, 4, 3, 2, 1, 0
ADDRESS = 0010100 (0x14)
PRE_C1508
Eight most significant bits of the 16-bit Preamble-C, when nonaudio data is detected according to the IEC60937
standard; otherwise, bits show zeros.
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ADAV801
Rev. 0 | Page 38 of 56
d Only)
PRE_C07PRE_C00
Table 36. Preamble-C LSB Register (Rea
7, 6, 5, 4, 3, 2, 1, 0
ADDRESS = 0010101 (0x15)
PRE_C0700
Eight least signif
nt bits of th
-bit Preamb -C, when nonaudio data is detected according to the IEC60937
d; otherwise, bits show zeros.
ica
e 16
le
standar
Table 37. Preamble-D M
PR
SB Register (Read Only)
E_D15PRE_D08
7, 6, 5, 4, 3, 2, 1, 0
ADDRESS = 0010110 (0x16)
PRE_D1508
Ei
nonaudio data is detected according to the IEC60937
st
nonaudio is used, this becomes the eight most significant bits
of
ght most significant bits of the 16-bit Preamble-D, when
andard; otherwise, bits show zeros. When subframe
the 16-bit Preamble-C of Channel B.
Table 38. Preamble-D LSB Register (Read Only)
PRE_D07PRE_D00
7, 6, 5, 4, 3, 2, 1, 0
ADDRESS = 0010111 (0x17)
PRE_D0700
Ei
mble-D, when nonaudio data is detected according to the IEC60937
standard; otherwise, bits
becomes the eight most significant bits
of
ght least significant bits of the 16-bit Prea
show zeros. When subframe nonaudio is used, this
the 16-bit Preamble-C of Channel B.
Table 39. Receiver Erro
Rx
amble
CRCError NoStream BiPhase/
Parity Lock
r Register (Read Only)
Validity
Emphasis
NonAudio
Pre
NonAudio
7
3 2 1
0
6 5 4
ADDRESS = 0011000 (0x18)
RxValidity
Th
ived stream.
is is the VALIDITY bit in the AES3 rece
Emphasis
This bit is set, if the audio data is pre-emphasized. Once it has been read, it remains high and does not generate an
interrupt unless it changes state.
onaudio) is set. Once it has been read, it does not generate another
upt unle
data bec
audio or
pe of no
ha
nAudio
is bit is set,
e audio da
s nonaudio due to the det
ion of a pream
. The nonau
preamble type register
s what type of preamble was detected. Once read, it remains in its state and does not generate an interrupt
ster
NonAudio
This bit is set, when Channel Status Bit 1 (n
interr
ss the
omes
the ty
naudio data c
nges.
No
Preamble
indicate
Th
if th
ta i
ect
ble
dio
unless it changes state.
This bit is the error flag for the channel status CRCError check. This bit does not clear until the receiver error regi
CRCError
is read.
This bit is set, if there is no AES3/SPDIF stream present at the AES3/SPDIF receiver. Once read, it remains high and
NoStream
does not generate an interrupt unless it changes state.
This bit is set, if a biphase or parity error occurred in the AES3/SPDIF stream. This bit is not cleared until the register is
BiPhase/Parity
read.
This bit is set, if the PLL has locked or cleared when the PLL loses lock. Once read, it remains in its state and does not
generate an interrupt unless it changes state.
Lock
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ADAV801
Rev. 0 | Page 39 of 56
RxValid
Emphasis
Mask
nAudio
Mask
onA
Preamble
Mask
CRCError
Mask
Stream
Mask
BiPhas
Parity
Mask Lock
Mask
Table 40. Receiver Error Mask Register
Mask
ity
No
N
udio
No
e/
7 6 5 4 3 2 1 0
ADDRESS = 0011001 (0x19)
RxValidity Mask
rating an interrupt.
Masks the RxValidity bit from gene
0 = RxValidity bit does not generate an interrupt.
terrupt.
k
an interrupt.
0 = NonAudio bit does not generate an interrupt.
1 = NonAudio bit generates an interrupt.
nAudio preamble bit from generating an interrupt.
0 = NonAudio preamble bit does not gene
e an interru
onAudio preamble bit generates an interrupt.
ask
NoStream Mask
BiPhase/Parity Mask
an interrupt.
1 = RxValidity bit generates an interrupt.
Emphasis Mask
Masks the emphasis bit from generating an in
0 = Emphasis bit does not generate an interrupt.
1 = Emphasis bit generates an interrupt.
NonAudio Mas
Masks the NonAudio bit from generating


NonAudio Preamble
Masks the No
Mask
rat
pt.
1 = N
CRCError M
Masks the CRCError bit from generating an interrupt.
0 = CRCError bit does not generate an interrupt.
1 = CRCError bit generates an interrupt.
Masks the NoStream bit from generating an interrupt.
0 = NoStream bit does not generate an interrupt.
1 = NoStream bit generates an interrupt.
Masks the BiPhase/Parity bit from generating
0 = BiPhase/Parity bit does not generate an interrupt.
1 = BiPhase/Parity bit generates an interrupt.
Lock Mask
Masks the Lock bit from generating an interrupt.

0 = Lock bit does not generate an interrupt.
1 = Lock bit generates an interrupt.
Table 41. Sample Rate Co
RES RES RES RES TOO_SLOW
OVRL
OVRR
MUTE_IND
nverter Error Register (Read Only)
7 6 5 4 3
2 1 0
ADDRESS = 0011010 (0x1A)
TOO_SLOW
This bit is set, when the clock to the SRC is too slow, that is, there are not enough clock cycles to complete the
internal convolution.
OVRL
This bit is set, when the left output data of the sample rate converter has gone over the full-scale range and has been
clipped. This bit is not cleared until the register is read.
OVRR
This bit is set, when the right output data of the sample rate converter has gone over the full-scale range and has
been clipped. This bit is not cleared until the register is read.
MUTE_IND
Mute indicated. This bit is set, when the SRC is in fast mode and clicks or pops can be heard in the SRC output data.
The output of the SRC can be muted, if required, until the SRC is in slow mode. Once read, this bit remains in its state
and does not generate an interrupt until it has changed state.
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ADAV801
Rev. 0 | Page 40 of 56
sk Register
RES RES RES RES OVRL
Mask
sk
E_
Table 42. Sample Rate Converter Error Ma
RES
OVRR
Ma
MUT
IND
MASK
7 6
3 2
0
5
4
1
ADDRESS = 0011011 (0x1B)
OVRL Mask
Masks the OVRL from generating an interrupt.
0 = OVRL bit does not generate an interrupt.
1 = OVRL bit generates an interrupt.
OVRR Mask
Masks the OVRR from generating an interrupt.
ASK
interrupt.
0 = OVRR bit does not generate an interrupt.
1 = OVRR bit generates an interrupt. Reserved.
MUTE_IND M
Masks the MUTE_IND from generating an
0 = MUTE_IND bit does not generate an interrupt.
1 = MUTE_IND bit generates an interrupt.
Table 43. Interrupt St
TxCSINT
RxCSDIFF RxUBINT RxCSBINT RxERROR
atus Register
SRCError
TxCSTINT
TxUBINT
7 6 5 4 3 2 1 0
ADDRESS = 0011100 (0x1C)
SRCError
This bit is set, if one of the sample rate converter interrupts is asserted, and the host should immediately read the
gh until the interrupt status register is read.
sample rate converter error register. This bit remains hi
TxCSTINT
This bit is set, if a write to the transmitter channel status buffer was made while transmitter channel status bits were
fer to the SPDIF transmit buffer.
his bit remains high until the interrupt status register is read.
it buffer has transmitted its block of channel status. This bit remains
ceiver Channel Status B clock. This bit
remains high until read, but does not generate an interrupt.
eiver user bit buffer has a new block or message. This bit remains high until the interrupt
RxCSBIN
it is set, if
block of c
tus is rea
O
0, or if the
s
when
BCONF3 = 1.
is bit remains
gh until the interrupt status register is read.
is set, if one of the AES3/SPDIF receiver interrupts is asserted, and the host should immediately read the
ins high until the interrupt status register is read.
being copied from the transmitter CS buf
TxUBINT
This bit is set, if the SPDIF transmit buffer is empty. T
TxCSINT
This bit is set, if the transmitter channel status b
high until the interrupt status register is read.
This bit is set, if the receiver Channel Status A block is different from the re
RxCSDIFF
RxUBINT
This bit is set, if the rec
status register is read.
T
This b
a new
hannel sta
d when RxBC NF3 =
channel status ha changed
Rx
Th
hi
RxERROR
This bit
receiver error register. This bit rema
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ADAV801
Rev. 0 | Page 41 of 56
xCSTINT
sk
TxUBINT
Mask
TxCSBINT
Mask RES
RxUBINT
Mask
RxCSBINT
Mask
RxError
Mask
Table 44. Interrupt Status Mask Register
SRCError
T
Mask
Ma
7 6 5 4 3 2 1 0
ADDRESS = 0011101 (0x1D)
SRCError Mask
Masks the SRCError bit from generating an interrupt.
0 = SRCError bit does not generate an interrupt.
an interrupt.
k
INT bit from generating an interrupt.
oes not generate an interrupt.
n interrupt.
ask
1 = TxUBINT bit generates an interrupt.
rrupt.
rrupt.
nterrupt.
T bit from generating an interrupt.
BINT bit does not generate an interrupt.
xCSBINT Mask
Masks the RxCSBINT bit from generating an interrupt.
nerate an interrupt.
nterrupt.
rating an interrupt.
s not generate an interrupt.
rror bit generates an interrupt.
1 = SRCError bit generates
TxCSTINT Mas
Masks the TxCST
0 = TxCSTINT bit d
1 = TxCSTINT bit generates a
TxUBINT M
Masks the TxUBINT bit from generating an interrupt.
0 = TxUBINT bit does not generate an interrupt.

TxCSBINT Mask
Masks the TxCSBINT bit from generating an inte
0 = TxCSBINT bit does not generate an inte
1 = TxCSBINT bit generates an i
RxUBINT Mask
Masks the RxUBIN
0 = RxU
1 = RxUBINT bit generates an interrupt.
R
0 = RxCSBINT bit does not ge
1 = RxCSBINT bit generates an i
Masks the RxError bit from gene
RxError Mask
0 = RxError bit doe
1 = RxE
able 45. Mute and De-Emphasis Register
RES RES SRC_DEEM10
RES
T
RES RES TxMUTE
7 6 5
4 3 2,
1
0
ADDRESS = 0011110 (0x1E)
TxMUTE
Mutes the AES3/SPDIF transmitter.

0 = Transmitter is not muted.
1 = Transmitter is muted.
SRC_DEEM10
Selects the de-emphasis filter for the input data to the sample rate converter.
mphasis.
kHz de-emphasis.
00 = No de-emphasis.
01 = 32 kHz de-emphasis.
10 = 44.1 kHz de-e
11 = 48
Table 46. NonAudio Preambl
RES
DTS-CD
Preamble
NonAudio
Frame
NonAudio
Subframe_A
NonAudio
Subframe_B
e Type Register (Read Only)
RES RES RES
7 6 5 4 3 2 1
0
ADDRESS = 0011111 (0x1F)
DTS-CD Preamble
This bit is set, if the DTS-CD preamble is detected.
NonAudio Frame
dio
me_A
subframe nonaudio data
onAudio
Subframe_B
This bit is set, if the data received through Channel B of the AES3/SPDIF receiver is subframe nonaudio data
according to SMPTE337M.
This bit is set, if the data received through the AES3/SPDIF receiver is nonaudio data according to the IEC61937
standard or nonaudio data according to SMPTE337M.
NonAu
Subfra
This bit is set, if the data received through Channel A of the AES3/SPDIF receiver is
according to SMPTE337M.
N
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ADAV801
Rev. 0 | Page 42 of 56
tatus Buffer
RCS
SB0
Table 47. Receiver Channel S
B7RC
7, 6, 5, 4, 3, 2, 1, 0
ADDRESS
000 to 01
(0x20 to
= 0100
10111
0x37)
RCSB70
The 24-byte receiver channel status buffer. The PRO b
d at ad
tion 0
This bu
d
only if the channel status is not autob
betwee
ceiver an
mitter.
it is store
dress loca
x20, Bit 0.
ffer is rea
uffered
n the re
d trans

Table 48. T
ter Ch
tus Bu
TCS
B0
ransmit
annel Sta
ffer
B7TCS
7, 6, 5, 4, 3, 2, 1, 0
ADDRESS
to 10
38 to
= 0111000
01111 (0x
0x4F)
TCSB70
The 24-byte transmi
el stat
The PR
tored a
location 0x38, Bit 0. This buffer is
disa
autob
etwee
iver and transmitter is
tter chann
us buffer.
O bit is s
t address
bled when
uffering b
n the rece
enabled.
Table 49. Receiver User Bit Buffer Indire
ess Regi
RxUBADDR07RxUBADDR00
ct Addr
ster
7, 6, 5, 4, 3, 2, 1, 0
ADDRESS = 1010000 (0x50)
RxUBADDR0700
ng to th
ss loca
he rece
r bit bu
Indirect address pointi
e addre
tion in t
iver use
ffer.
Table 50. Receiver Us
07RxUBDATA00
er Bit Buffer Data Register
RxUBDATA
7, 6, 5, 4, 3, 2, 1, 0
ADDRESS = 1010001 (0x51)
RxUBDATA0700
egister reads eight bits of user data from the receiver user bit buffer pointed to by RxUBADDR07
ering of the user bits is enabled; otherwise, it is a read-only buffer.
A read from this r
00. This buffer can be written to when autobuff
Table 51. Transmitte
Indirect Address Register
BADDR00
r User Bit Buffer
TxUBADDR07TxU
7, 6, 5, 4, 3, 2, 1, 0
ADDRESS = 1010010 (0x52)
TxUBADDR0700
ress pointing to the address location in the transmitter user bit buffer.
Indirect add
Table 52. Transmitter User Bit Buffer
DATA00
Data Register
07TxUB
TxUBDATA
7, 6, 5, 4, 3, 2, 1, 0
ADDRESS = 1010011 (0x53)
TxUBDATA0700
A write to this register writes eight bits of user data to the transmit user bit buffer pointed to by TxUBADDR0700.
When user bit autobuffering is enabled, this buffer is disabled.
Table 53. Q Subcode CRCError Status Register (Read-Only)
RES RES RES RES RES RES QCRCERROR
QSUB
7 6 5 4
3 2 1
0
ADDRESS = 1010100 (0x54)
QCRCERROR
This bit is set, if the CRC check of the Q subcode fails. This bit remains high, but does not generate an interrupt. This
bit is cleared once the register is read.
QSUB
This bit is set, if a Q subcode has been read into the Q subcode buffer (see Table 54).
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ADAV801
Rev. 0 | Page 43 of 56
s
Bit 7
it 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit
Bi
Table 54. Q Subcode Buffer
Addres
B
1
t 0
0x55
Address Address Address
ss Control Control Control Control
Addre
0x56
Track
Tra
number
ck
Track
Track
number
Track
number
Track
number
Track
number
Track
number
number
number
0x57
Index Index Index Index Index Index Index Index
0x58 Minute
te Minute Minute Minute Minute Minute Minute
Minu
0x59
Second Second Second Second Second Second Second Second
0x5A
Frame Frame Frame Frame Frame Frame Frame Frame
0x5B
Zero Zero Zero Zero Zero Zero Zero Zero
0x5C
Absolute
minute
minute
Absolute
minute
Absolute
minute
Absolute
minute
Absolute
minute
Absolute
minute
Absolute
Absolute
minute
0x5D
Absolute
second
te
Absolute
second
Absolute
second
Absolute
second
Absolute
second
Absolute
second
Absolute
second
Absolu
second
0x5E
Absolute
frame
Absolute
frame
Absolute
frame
Absolute
frame
Absolute
frame
Absolute
frame
Absolute
frame
Absolute
frame
Table 55. Datapath Control Register 1
SRC1 SRC0 REC2 REC1 REC0 AUXO2
AUXO1
AUXO0
7 6 5 4 3 2 1 0
ADDRESS = 1100010 (0x62)
SRC10
Datapath source select for sample rate converter (SRC).
00 = ADC.

01 = DIR.
10 = Playback.
11 = Auxiliary in.
REC20
Datapath source select for record output port.
.
auxiliary output port.
000 = ADC.
001 = DIR.
010 = Playback.
011 = Auxiliary in
100 = SRC.
AUXO20
Datapath source select for
000 = ADC.
001 = DIR.
010 = Playback.
011 = Auxiliary in.
100 = SRC.
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ADAV801
Rev. 0 | Page 44 of 56
r 2
DAC0 DIT2 DIT1 DIT0
Table 56. Datapath Control Registe
RES RES DAC2 DAC1
7 6 5 4 3 2 1 0
ADDRESS = 1100011 (0x63)
DAC20
Datapath source select for DAC.
00 = ADC.
01 = DIR.
10 = Playback.
11 = Auxiliary in.
IT.
100 = SRC.
DIT20
Datapath source select for D
000 = ADC.
001 = DIR.
010 = Playback.
011 = Auxiliary in.
100 = SRC.
Table 57. DAC Contr
DR_DIG
CHSEL1
CHSEL0 POL1
POL0
MUTER MUTEL
ol Register 1
DR_ALL
7 6 5 4 3 2 1 0
ADDRESS = 1100100 (0x64)
DR_ALL
Hard reset a
wer-down
nd po
.
0 = Normal, output pins go to V
REF
level.
d reset and low power, output pins go to AGND.
except registers.
l, left-right.
ght.
right-left.
polarity.
00 = Both positive.
tive.
= Right ne
ht channel.
1 = Har
DR_DIG
DAC digital reset.
0 = Normal.
1 = Reset all
CHSEL10
DAC channel select.
00 = Norma
01 = Both ri
10 = Both left.
11 = Swapped,
POL10
DAC channel

01 = Left nega
10
gative.
11 = Both negative.
MUTER
Mute rig
0 = Normal.
1 = Mute.
MUTEL
Mute left channel.
0 = Normal.
1 = Mute.
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ADAV801
Rev. 0 | Page 45 of 56
Table 58. DAC Control Register 2
RES RES DMCLK1
DMCLK0
DFS1
DFS0
DEEM1
DEEM0
7 6 5 4
3 2
1 0
ADDRESS = 1100101 (0x65)
DMCLK10
DAC MCLK divider.
00 = MCLK.
01 = MCLK/1.5.
10 = MCLK/2.
11 = MCLK/3.
elect.
CLK
).
= 4 (MCLK
128 f
S
).
(MCLK = 64 f
S
).
EEM10
elect.
10 = 32 kHz.
11 = 48 kHz.
DFS10
DAC interpolator s
00 = 8 (M
= 256 f
S
01
=
10 = 2
11 = Reserved.
D
DAC de-emphasis s
00 = None.
01 = 44.1 kHz.
Table 59. DAC Contr
Register 3
RES RES RES RES ZFVOL
ZFDATA
ZFPOL
ol
RES
7
4 3 2 1 0
6 5
ADDRESS = 1100110 (0x66)
ZFVOL
DAC zero flag on mute and zero volume.
0
1 = Disabled.
disable.
0 = Enabled.
1 = Disabled.
lag polarity.
0
1
= Enabled.

ZFDATA
DAC zero flag on zero data


ZFPOL
DAC zero f
= Active high.
= Active low.

Table 60. DAC Contr
RES INTRPT
ZEROSEL1
ZEROSEL0
RES RES RES RES
ol Register 4
7 6 5 4 3 2 1 0
ADDRESS = 1100111 (0x67)
INTRPT
This bit selects th
unctionality
the ZEROL/
pin.
e f
of
INT
0 = Pin functions as a ZEROL flag pin.
1
in.
T
lity of the ZEROR pin when the ZEROL/INT pin is used as an interrupt.
00 = Pin functions as a ZEROR flag pin.
01 = Pin functions as a ZEROL flag pin.
1
hen either the left or right channel is zero.
1
right channels are zero.
= Pin functions as an interrupt p
ZEROSEL10
hese bits control the functiona


0 = Pin is asserted w
1 = Pin is asserted when both the left and
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ADAV801
Rev. 0 | Page 46 of 56
LL7
5
4
3
2
1
0
Table 61. DAC Left Volume Register
DVO
DVOLL6 DVOLL
DVOLL
DVOLL
DVOLL
DVOLL
DVOLL
7 6 5 4 3 2 1 0
ADDRESS = 1101000 (0x68)
DVOLL70
.
DAC left channel volume control
1111111 = 0 dBFS.
1111110 = -0.375 dBFS.
0000 = -95.625 dBFS.
000

Table 62. DAC Right Volume Register
LR7 DVOLR6 DVOLR5 DVOLR4 DVOLR3 DVOLR2 DVOLR1 DVOLR0
DVO
7 6 5 4 3 2 1 0
ADDRESS = 1101001 (0x69)
DVOLR70
DAC right channel volume control.
1111111 = 0 dBFS.
1111110 = -0.375 dBFS.
0000000 = -95.625 dBFS.
Table 63. DAC Left P
DLP5 DLP4 DLP3 DLP2 DLP1 DLP0
eak Volume Register
RES RES
7 6 5 4 3 2 1 0
ADDRESS = 1101010 (0x6A)
DLP50
DAC left channel peak volume detection.
000000 = 0 dBFS.
000001 = -1 dBFS.
.
111111 = -63 dBFS

Table 64. DAC Right Peak Volume Register
DRP5 DRP4 DRP3 DRP2 DRP1 DRP0
RES RES
7 6 5 4 3 2 1 0
ADDRESS = 1101011 (0x6B)
DRP50
DAC right channel peak volume detection.
000000 = 0 dBFS.

000001 = -1 dBFS.
111111 = -63 dBFS.

Table 65. ADC Left Chan
ter
AGL5 AGL4 AGL3 AGL2 AGL1 AGL0
nel PGA Gain Regis
RES RES
7 6 5 4
3 2 1 0
ADDRESS = 1101100 (0x6C)
AGL50
PGA left channel gain control.
000000 = 0 dB.
000001 = 0.5 dB.
...
101111 = 23.5 dB.
110000 = 24 dB.
...
111111 = 24 dB.
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ADAV801
Rev. 0 | Page 47 of 56
Gain Register
Table 66. ADC Right Channel PGA
RES RES AGR5
AGR4 AGR3
AGR2
AGR1 AGR0
7 6 5 4 3 2 1 0
ADDRESS = 1101101 (0x6D)
AGR50
PGA right channel gain control.
000000 = 0 dB.
000001 = 0.5 dB.
...
101111 = 23.5 dB.
110000 = 24 dB.
...
111111 = 24 dB.
Table 67. ADC Control Register 1
AMC
HPF
PWRDWN
ANA_PD
MUTER
MUTEL
PLPD
PRPD
7 6 5 4 3 2 1 0
ADDRESS = 1101110 (0x6E)
AMC
ADC modulator clock.
0 = ADC MCLK/2 (128 f
S
).
1 = ADC MCLK/4 (64 f
S
).
HPF
1 = HPF enabled.
ow
wer-down.
UTER

ormal.
Po er-dow
ht power-down.
High-pass filter enable.
0 = Normal.

PWRDWN
ADC power-down.
l.
0 = Norma
1 = Power-d
n.
ion po
ANA_PD
ADC analog sect
0 = Normal.
1 = Power-down.

M
Mute ADC right channel.
0 = Normal.
1 = Muted.
MUTEL
Mute ADC left channel.
0 = Normal.
1 = Muted.
PLPD
PGA left power-down.
0 = N
1 =
w
PRPD
PGA rig
n.
0 = Normal.
1 = Power-down.
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ADAV801
Rev. 0 | Page 48 of 56
R
B
Table 68. ADC Control Register 2
RES RES ES UF_PD
RES RES MCD1
MCD0
7 6 5 4 3 2 1 0
ADDRESS = 1101111 (0x6F)
BUF_PD
Reference buffer power-down control.
0 = Normal.
n.
MCD10
ck divider.
3.
y 1.
1 = Power-dow
ADC master clo
00 = Divide by 1.
01 = Divide by 2.
10 = Divide by
11 = Divide b

Table 69. ADC Left V
er
AVOLL6 AVOLL5 AVOLL4 AVOLL3 AVOLL2 AVOLL1 AVOLL0
olume Regist
AVOLL7
7 6 5 4 3 2 1 0
ADDRESS = 1110000 (0x70)
AVOLL70
olume control.
ADC left channel v
1111111 = 1.0 (0 dBFS).
996 (-0.00348 dBFS).
dBFS).
0039 (-48.18 dBFS).
1111110 = 0.
1000000 = 0.5 (-6
0111111 = 0.496 (-6.09 dBFS).
0000000 = 0.

Table 70. ADC Right
AVOLR6 AVOLR5 AVOLR4 AVOLR3 AVOLR2 AVOLR1 AVOLR0
Volume Register
AVOLR7
7 6 5 4 3 2 1 0
ADDRESS = 1110001 (0x71)
AVOLR70
ADC right chan
me co
nel volu
ntrol.
11111 1 = 1.0
BFS).
0 = 0.996 (-0.00348 dBFS).
96 (-6.09 dBFS).
).
1
111111
(0 d
1000000 = 0.5 (-6 dBFS).
0111111 = 0.4
0000000 = 0.0039 (-48.18 dBFS

Table 71. ADC Left P
gister
5 ALP4 ALP3 ALP2 ALP1 ALP0
eak Volume Re
RES RES ALP
7 6 5 4 3 2 1 0
ADDRESS = 1110010 (0x72)
ALP50
ADC left channel peak volume detection.
000000 = 0 dBFS.
BFS.
000001 = -1 d
111111 = -63 dBFS.

Table 72. ADC Right
egister
RES ARP5 ARP4 ARP3 ARP2 ARP1 ARP0
Peak Volume R
RES
7 6 5 4 3 2 1 0
ADDRESS = 1110011 (0x73)
ARP50
ADC right channel peak volume detection.
000000 = 0 dBFS.

000001 = -1 dBFS.
111111 = -63 dBFS.
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ADAV801
Rev. 0 | Page 49 of 56
LK1
LK0
DIV
Table 73. PLL Control Register 1
DIRIN_C
DIRIN_C
MCLKO
PLLDIV
PLL2PD
PLL1PD
XTLPD SYSCLK3
7 6 5
4
3 2 1 0
ADDRESS = 1110100 (0x74)
DIRIN_CLK1-0
nt to SYSCLK3.
Recovered SPDIF clock se
00 = SYSCLK3 comes from PLL block.
.
the recovered SPDIF clock from DIRIN.
CLKODIV
generate MCLKO.
.
y 2 to generate the PLL master clock.
.
LL2.
own.
n XTAL oscillator.
down.
for SYSCLK3.
01 = Reserved
10 = Reserved.
11 = SYSCLK3 is
M
Divide input MCLK by 2 to
0 = Disabled.
1 = Enabled
PLLDIV
Divide XIN b
0 = Disabled.
1 = Enabled
PLL2PD
Power-down P
0 = Normal.
1 = Power-down.
PLL1PD
Power-down PLL1.
0 = Normal.
1 = Power-d
XTLPD
Power-dow
0 = Normal.
1 = Power-
SYSCLK3
Clock output
0 = 512 f
S
.
1 = 256 f
S
.
Table 74. PLL Control Register 2
SEL2
DOUB2
FS1 FS0 SEL1
DOUB1
FS2_1
FS2_0
7 6 5 4 3 2 1 0
ADDRESS = 1110101 (0x75)
FS2_10
Sampl rate se
t for PLL2.
e
lec
00 = 48 kHz.
z.
.
io select for PLL2.
UB2
lected sample rate on PLL2.
d.
select for PLL1.
rved.
.
11 = 44.1 kHz.
SEL1
Oversample ratio select for PLL1.
0 = 256 f
S
.
1 = 384 f
S
.
DOUB1
Double-selected sample rate on PLL1.
0 = Disabled.
1 = Enabled.
01 = Reserved.
10 = 32 kH
11 = 44.1 kHz
SEL2
Oversample rat
0 = 256 f
S
.
1 = 384 f
S
.
DO
Double-se
0 = Disabled.
1 = Enable
FS10
Sample rate
00 = 48 kHz.
01 = Rese
10 = 32 kHz
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ADAV801
Rev. 0 | Page 50 of 56
egister 1
D
C
AC
ACLK1 ACLK0 I
_1
_0
Table 75. Internal Clocking Control R
DCLK2 CLK1 D LK0
LK2
CLK2
ICLK2
7 6
5 4 3 2 1 0
ADDRESS = 1110110 (0x76)
DCLK20
DAC clock source select.
000 = XIN.
I.
LINT2.
LL (512 f
S
).
101 = DIR PLL (256 f
S
).
XIN.
C clock source select.
IN.
1.
r for internal clock ICLK2.
001 = MCLK
010 = PLLINT1.
011 = PL
100 = DIR P

110 = XIN.
111 =
ACLK20
AD
000 = X
001 = MCLKI.
010 = PLLINT
011 = PLLINT2.
100 = DIR PLL (512 f
S
).
101 = DIR PLL (256 f
S
).
110 = XIN.
111 = XIN.
ICLK2_10
Source selecto
00 = XIN.
01 = MCLKI.
10 = PLLINT1.
11 = PLLINT2.
Table
76. Internal Clo
l Register 2
RES ICLK1_1
ICLK1_0
PLL2INT1
PLL2INT0
PLL1INT
cking Contro
RES RES
7 6 5 4 3 2 1 0
ADDRESS = 1110111 (0x77)
ICLK1_10
Source selector for internal clock ICLK1.
00 = XIN.
01 = MCLKI.
10 = PLLINT1.
11 = PLLINT2.
PLL2INT10
PLL2 internal selector (see Figure 38).
00 = FS2.
01 = FS2/2.
10 = FS3.
11 = FS3/2.
PLL1INT
PLL1 internal selector.
0 = FS1.
1 = FS1/2.
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ADAV801
Rev. 0 | Page 51 of 56
er
ce
PLL2_Source
ES
RES
RES
Table 77. PLL Clock Source Regist
PLL1_Sour
RES RES R
RES
7
6
5 4 3 2 1 0
ADDRESS = 1111000 (0x78)
PLL1_Source
Selects the clock source for PLL1.
0 = XIN.
1 = MCLKI.
PLL2_Source
ck source for PLL2.
Selects the clo
0 = XIN.
1 = MCLKI.
Table 78. PLL Output
Register
RES
DIRINPD DIRIN_PIN
RES
SYSCLK1 SYSCLK2 SYSCLK3
Enable
RES
7 6 5 4 3 2 1 0
ADDRESS = 1111010 (0x7A)
DIRINPD
This bit powers down the SPDIF receiver.
0 = Normal.
1 = Power-down.
DIRIN_PIN
This bit determines the input levels of the DIRIN pin.
down to 200 mV according to AES3 requirements.
ons section.
YSCLK1
YSCLK2
LK2 output.
0 = Enabled.
YSCLK3
es the SYSCLK3 ou
Enabled.
bled.
0 = DIRIN accepts input signals
1 = DIRIN accepts input signals as defined in the Specificati
S
Enables the SYSCLK1 output.
0 = Enabled.
1 = Disabled.
S
Enables the SYSC

1 = Disabled.
S
Enabl
tput.
0 =
1 = Disa
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ADAV801
Rev. 0 | Page 52 of 56
GAINCNTR10
RECMODE10 LIMDET
ALCEN
Table 79. ALC Control Register 1
FSSEL10
7, 6
5, 4
3, 2
1
0
ADDRESS = 1111011 (0x7B)
FSSEL10
These bits should equal the sample rate of the ADC.
00 = 96 kHz.
01 = 48 kHz.
10 = 32 kHz.
11 = Reserved.
GAINCNTR10
These bits determine the limit of the counter used in limited recovery mode.
00 = 3.
01 = 7.
10 = 15.
11 = 31.
RECMODE10
These bits determine which recovery mode is used by the ALC section.
00 = No recovery.
01 = Normal recovery.
10 = Limited recovery.
11 = Reserved.
LIMDET
These bits limit detect mode.
0 = ALC is used when either channel exceeds the set limit.
1 = ALC is used only when both channels exceed the set limit.
ALCEN
These bits enable ALC.
0 = Disable ALC.
1 = Enable ALC.

Table 80. ALC Control Register 2
RES
RECTH10
ATKTH10
RECTIME10
ATKTIME
7
6, 5
4, 3
2, 1
0
ADDRESS = 1111100 (0x7C)
RECTH10
Recovery threshold.
00 = -2 dB.
01 = -3 dB.
10 = -4 dB.
11 = -6 dB.
ATKTH10
Attack threshold.
00 = 0 dB.
01 = -1 dB.
10 = -2 dB.
11 = -4 dB.
RECTIME10
Recovery time selection.
00 = 32 ms.
01 = 64 ms.
10 = 128 ms.
11 = 256 ms.
ATKTIME
Attack timer selection.
0 = 1 ms.
1 = 4 ms.
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ADAV801
Rev. 0 | Page 53 of 56
Table 81. ALC Control Register 3
ALC
RESET
7, 6, 5, 4, 3, 2, 1, 0
ADDRESS = 1111101 (0x7D)
ALC RESET
A write to this register restarts the ALC operation. The value written to this register is irrelevant. A read from this
register gives the gain reduction factor.
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ADAV801
Rev. 0 | Page 54 of 56
LAYOUT CONSIDERATIONS
Getting the best performance from the ADAV801 requires a
careful layout of the printed circuit board (PCB). Using separate
analog and digital ground planes is recommended, because
these give the currents a low resistance path back to the power
supplies. The ground planes should be connected in only one
place, usually under the ADAV801, to prevent ground loops.
The analog and digital supply pins should be decoupled to their
respective ground pins with a 10 F to 47 F tantalum capacitor
and a 0.1 F ceramic capacitor. These capacitors should be
placed as close as possible to the supply pins.
ADC
The ADC uses a switch capacitor input stage and is, therefore,
particularly sensitive to digital noise. Sources of noise, such as
PLLs or clocks, should not be routed close to the ADC section.
The CAPxN and CAPxP pins form a charge reservoir for the
switched capacitor section of the ADC, so keeping these nodes
electrically quiet is a key factor in ensuring good performance.
The capacitors connected to these pins should be of good
quality, either NPO or COG, and should be placed as close as
possible to CAPxN and CAPxP.
DAC
The DAC requires an analog filter to filter out-of-band noise
from the analog output. A third-order Bessel filter is
recommended, although the filter to use depends on the
f the application.
PLL
The PLL can be used to generate digital clocks, either for use
internally or to clock external circuitry. Because every clock is a
potential source of noise, care should be taken when using the
PLL. The ADAV801's PLL outputs can be enabled or disabled, as
required. If the PLL clocks are not required by external circuitry,
it is recommended that the outputs be disabled. To reduce
cross-coupling between clocks, a digital ground trace can be
routed on either side of the PLL clock signal, if required.
The PLL has its own power supply pins. To get the best
performance from the PLL and from the rest of the ADAV801,
it is recommended that a separate analog supply be used. Where
this is not possible, the user must decide whether to connect the
PLL supply to the analog (AV
DD
) or digital (DV
DD
) supply.
Connecting the PLL supply to AV
DD
gives the best jitter
performance, but can degrade the performance of the ADC and
DAC sections slightly due to the increased digital noise created
on the AV
DD
by the PLL. Connecting the PLL supply to DV
DD
keeps digital noise away from the analog supply, but the jitter
specifications might be reduced depending on the quality of the
digital supply. Using the layout recommendations described in
this section helps to reduce these effects.
RESET AND POWER-DOWN CONSIDERATIONS
When the ADAV801 is held in reset by bringing the RESET
requirements o
pin low, a number of circuit blocks remain powered up. For
example, the crystal oscillator circuit based around the XIN
and XOUT pins is still active, so that a stable clock source is
available when the ADAV801 is taken out of reset. Also, the
VCO associated with the SPDIF receiver is active so that the
receiver locks to the incoming SPDIF stream in the shortest
possible time. Where power consumption is a concern, the
individual blocks of the ADAV801 can be powered down via
the control registers to gain significant power savings. Table 82
shows typical power savings when using the power-down bits
in the control registers.
Table 82. Typical Power Requirements
Operating
Mode
AV
DD
(mA)
DV
DD
(mA)
ODV
DD
(mA)
DIR_V
DD
(mA)
Power
(mW)
Normal 50
25
5
5 280.5
Reset low
30
4
2.5
1
123.75
Power-down
bits
12 0.1
1.3 0.7 46.53
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ADAV801
Rev. 0 | Page 55 of 56
OUTLINE DIMENSIONS
TOP VIEW
(PINS DOWN)
1
16
17
33
32
48
49
64
0.27
0.22
0.17
0.50
BSC
10.00
BSC SQ
1.60
MAX
SEATING
PLANE
0.75
0.60
0.45
VIEW A
12.00
BSC SQ
0.20
0.09
1.45
1.40
1.35
0.08 MAX
COPLANARITY
VIEW A
ROTATED 90 CCW
SEATING
PLANE
10
6
2
7
3.5
0
0.15
0.05
PIN 1
COMPLIANT TO JEDEC STANDARDS MS-026BCD
Figure 57. 64-Lead Low Profile Quad Flat Package [LQFP]
(ST-64-2)
Dimensions shown in millimeters
ORDERING GUIDE
Model
Temperature
Range
Control
Interface
DAC Outputs
Package Description
Package
Option
ADAV801ASTZ
1
-40C to +85C
SPI
Single-Ended
64-Lead Low Profile Quad Flat Package [LQFP]
ST-64-2
ADAV801ASTZ-REEL
1
-40C to +85C
SPI
Single-Ended
64-Lead Low Profile Quad Flat Package [LQFP]
ST-64-2
1
Z = Pb free part.
background image
ADAV801
Rev. 0 | Page 56 of 56
NOTES
2004 Analog Devices, Inc. All rights reserved. Trademarks and
registered trademarks are the property of their respective owners.
D0457707/04(0)

Document Outline