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¡ Semiconductor

MSM7580

¡ Semiconductor

MSM7580

ITU-T G.721 ADPCM TRANSCODER

GENERAL DESCRIPTION

The MSM7580 is an ADPCM transcoder which is used by the new digital cordless system. It
converts 64 kbps voice PCM serial data to 32 kbps ITU-T G.721 ADPCM serial data, and vice
versa.

This device consists of two systems with full-duplex voice data channels and a data-through
mode.

The MSM7580 provides cost effective solutions for digital cordless office telephone systems
which are incorporated into PABXs and for the public base stations which are connected to the
central office through digital PSTNs.

FEATURES

· Conforms to ITU-T G.721
· Built-in Full-duplex Transcoder with Two Data channels
· PCM companding Law: A-law/

-law selectable

· Synchronized Operation between coder and decoder, and between two channels.
· Serial PCM Data Transmission Speed: 64 kbps to 2048 kbps
· Serial ADPCM Data Transmission Speed: 32 kbps to 2048 kbps
· Hardware Reset ITU-T G.721 Optional Reset for each channel
· Power Down Control for each channel
· Decoder (ADPCM Æ PCM ) MUTE Mode and PAD Mode for each channel
· ADPCM Data-through Mode
· Capable of time slot conversion
· Special ADPCM Input Data Code ("0000") Detector for each channel
· Master Clock Signal : Not necessary
· Power supply voltage/Consumption current :

+5 V

10%, 2.5 mA/channel

· Package :

28-pin plastic SOP (SOP28-P-430-1.27-K) (Product name : MSM7580GS-K)

E2U0031-39-61

This version: Jun. 1999

Previous version: Aug. 1998

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¡ Semiconductor

MSM7580

PIN AND FUNCTIONAL DESCRIPTIONS

GND

Ground, 0 V.

SIP1, SOP1

PCM serial data input (SIP1) and output (SOP1) for Channel 1.
SOP1 is an open-drain output, which goes into a high impedance state after a continuous 8-bit
serial data output.

SIP2, SOP2

PCM serial data input (SIP2) and output (SOP2) for Channel 2.
SOP2 is an open-drain output, which goes into a high impedance state after a continuous 8-bit
serial data output.

PAD/ MUTE

Control input for the selection of PAD or MUTE mode.
When digital "1" is input, the PAD mode is selected and when digital "0" is input, the MUTE mode
is selected.

THR1, THR2

Control pins for the data through modes.
THR1 and THR2 are for Channel 1 and Channel 2, respectively. The data-through mode is
selected when digital "1" is applied to THR1 and THR2. In this mode, 8-bit serial input data
applied to SIA1 and SIA2 (ADPCM data input) is passed to the PCM serial data output pins,
SOP1 and SOP2, without any data modification. SOP1 and SOP2 go to the high impedance state
after the output of 8-bit data has been applied to SIA1 and SIA2.
Conversely 8-bit serial input data applied to SIP1 and SIP2 (PCM data input) is passed to
ADPCM serial data output pins, SOA1 and SOA2, without any data modification.
SOA1 and SOA2 go to the high impedance state after the output of 8-bit data has been applied
to SIP1 and SIP2.
Since ADPCM and PCM data interfaces have the mutually independent signal input pins for
synchronizing signals the time slots for data input and output can be exchanged between them.
Some timing at which data may be deleted or duplicated as described in "Notes on Usage" should
not be used.

MUTE1, MUTE2

Setting a digital "1"at these pins sets the PCM output to the idle pattern state regardless of the
ADPCM input data, when the MUTE mode is selected by the PAD/MUTE pin.
When the PAD mode is selected, the PCM output has a 12 dB loss.
Normally, these pins are set to a digital "0".
When the data through mode is selected, the function of these pins is invalid.

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MSM7580

SYNCP1, SYNCP2

Synchronous signal input.
SYNCP1 and SYNCP2 control the PCM data input/output timing for Channel 1 (SIP1, SOP1)
and Channel 2 (SIP2, SOP2), respectively.
Since other synchronous signal input pins SYNCA1 and SYNCA 2 for ADPCM interfaces are also
provided, the PCM and ADPCM data can be input or output with different timing.
PCM and ADPCM data interfaces can be used at a mutually independent timing except same
timing.

Note: When PCM and ADPCM data interfaces are used at a mutually independent timing, the

timing described in "Notes on Usage" should not be used.

BCLKP

Bit clock input.
This signal defines the PCM data transmission speed at the PCM data input/output pins.
BCLKP is used for Channels 1 and 2. Since BCLKA defines the data rate of the ADPCM data
interface, the PCM and ADPCM data can be input or output at different speeds.

LAW

PCM data companding law (A-law/m-law) selection.
Digital "1" and "0" correspond to A-law and

-law, respectively.

PDN1, PDN2

Power down mode selection.
PDN1 and PDN2 can be independently set to power down mode. When a digital "0" is applied,
these pins are in the power-down mode.

SIA1, SOA1

ADPCM serial data input (SIA1) and output (SOA1) pins for Channel 1.
SOA1 is an open-drain pin and enters to the high impedance state after outputting a continuous
4-bit serial data stream. When the data-through mode is selected, SOA1 enters to the high
impedance state after outputting an 8-bit serial data stream.

SIA2, SOA2

ADPCM serial data input (SIA2) and output (SOA2) pins for Channel 2.
These pins function the same as SIA1 and SOA1.

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MSM7580

SYNCA1 , SYNCA2

Synchronous signal input pins.
SYNCA1 and SYNCA 2 control the ADPCM data input/output timing for Channel 1 (SIA1,
SOA1) and Channel 2 (SIA2, SOA2), respectivery.
The ADPCM data can be input or output with timing other than the PCM data interface.
Therefore PCM and ADPCM interfaces can be used at a mutually independent timing except
some timing.
Since master clocks are generated by the internal PLL using SYNCA, a synchronous signal
should be input to there pins.

Note: When PCM and ADPCM data interfaces are used at a mutually independent timing, the

timing described in "Notes on Usage" should not be used.

DET1, DET2

Special ADPCM input data pattern detect pins.
When a 4-bit continuous "0" pattern at the ADPCM input pins Channel 1 (STA1) and Channel 2
(SIA2) is detected, DET1 and DET2 go from a digital "0" to a digital "1" state.
A digital "1" is output at the rising edge of the clock.
The fourth data bit (LSB) is clocked into the register by the bit clock (BCLKA) and the held there
until the rising edge in the next time frame.
When detecting the special data pattern in the next time frame, the digital "1" on the pins DET
(1, 2) is remains. When the THR1 pin or THR2 pin is at digital "1" level, the functions of these pins
are invalid.

RES1, RES2

Algorithm reset signal input pins for Channel 1 (RES1) and Channel 2 (RES2).
When a digital "0" is applied, the entire transcoder goes to its initial state.
This reset is defined by ITU-T G.721 and is an optional reset.

BCLKA

Bit clock input pin used to define the data transmission speed at the ADPCM interface.
This pin can be used for Channels 1 and 2, which allows the ADPCM data interface speed to be
defined differently than the PCM data interface speed.

Power supply.
The device must operate at +5 V

10%.

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MSM7580

ABSOLUTE MAXIMUM RATINGS

Symbol

Parameter

Condition

Rating

Unit

°C

0 to 7

0.3 to V

+ 0.3

55 to +150

DIN

STG

Power Supply Voltage

Digital Input Voltage

Storage Temperature

RECOMMENDED OPERATING CONDITIONS

Parameter

Power Supply Voltage

Operating Temperature

Digital Input High Voltage

Digital Input Low Voltage

Bit Clock Frequency

Synchronous

Signal Frequency

Clock Duty Ratio

Digital Input Rise Time

Digital Input Fall Time

Synchronous Signal Timing

CODER

Synchronous Signal Timing

DECODER

Synchronous

Signal Width

Data Set-up Time

Data Hold Time

Digital Output Load

Symbol

BCLKA

BCLKP

SYNC

Condition

All Digital Input Pins

BCLKA

BCLKP

SYNCP1, SYNCP2,

SYNCA1, SYNCA2

BCLKA, BCLKP

All Digital Input Pins

BCLKA, BCLKP to SYNCP

SYNCP to BCLKA, BCLKP

BCLKA, BCLKP to SYNCA

SYNCA to BCLKA, BCLKP

SYNCP1, SYNCP2,

SYNCA1, SYNCA2

SOP1, SOP2, SOA1, SOA2

(Pull-up Resistor)

SOP1, SOP2, SOA1, SOA2,

DET1, DET2

Min.

4.5

2.2

100

1 BCLK

100

500

Typ.

+25

8.0

Max.

5.5

+80

0.6

2048

100

Unit

°C

kHz

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¡ Semiconductor

MSM7580

ELECTRICAL CHARACTERISTICS

DC Characteristics

AC Characteristics

= 4.5 V to 5.5 V, Ta = 30°C to +80°C)

Parameter

Power Supply Current

Input High Voltage

Input Low Voltage

Input Leakage

Current

Digital

Output High Voltage

Digital

Output Low Voltage

Output Leakage Current

Input Capacitance

Symbol

DD1

DD2

OL1

OL2

Condition

Power On Mode: 2 Channels

Power Down Mode: 2 Channels

= V

= 0 V

DET1, DET2 : I

= 0.4 mA

1 LSTTL, Pull-up :

500 W

DET1, DET2 : I

= 1.6 mA

SOP1, SOP2, SOA1, SOA2

Min.

2.2

0.0

2.8

0.0

Typ

0.1

0.2

Max.

0.2

0.6

2.0

0.5

0.4

Unit

Symbol

Condition

1 LSTTL + 100 pF

Pull-up: 500

Parameter

Digital Output Delay Time

SDX

SDR

XD1

, t

RD1

XD2

, t

RD2

XD3

, t

RD3

DD1

DD2

Min.

Typ.

Max.

Unit

200

= 4.5 V to 5.5 V,Ta = 30°C to +80°C)

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¡ Semiconductor

MSM7580

TIMING DIAGRAM

,,,,,,,

,,,,,,

,,,,,,,

,,,

,,,,,,

,,,,,,,

,,,,,,

,,,

,,,,,,

CODER

DECODER

BCLKP

SYNCP

SIP

BCLKA

SYNCA

SOA

BCLKA

SYNCA

SIA

BCLKP

SYNCP

SOP

LSB

0 1 2 3 4 5 6 7 8 9 10

MSB

LSB

MSB

LSB

XD1

XD2

XD3

SDX

RD1

RD2

RD3

SDR

BCLKA

SYNCA

SIA

DET

"0000"

DD1

DD2

"0000"

Note)

Note:

4-bit data pattern except "0000"

DET ("0000" detection) Output Timing

MSB

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¡ Semiconductor

MSM7580

PAD/MUTE Processing Timing

78.125

121.09

78.125

Internal 12dBPAD Processing Timing

Internal MUTE Processing Timing

78.125

BCLKA

SYNCA

SIA

MSB

LSB

PAD Mode; MUTE1 and MUTE 2 Timings PAD/MUTE="H"

SYNCP

MUTE1, 2

BCLKP

SOP

0dB transmit data

12dB loss transmit data

MSB

LSB

0dB transmit data

MUTE Mode; MUTE1 and MUTE 2 Timings PAD/MUTE="L"

SYNCP

MUTE1, 2

BCLKP

SOP

0dB transmit data

MUTE (idle channel state)

MSB

LSB

0dB transmit data

As mentioned above, PAD and MUTE processings are carried out according to the rising edge
of SYNCA.
Even if BCLK is not 128 kHz, these processings are performed in the absolute time counted from
the rising edge of SYNCA.
Therefore, MUTE1 and MUTE 2 pins must be controlled so as to cover there processsings.

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¡ Semiconductor

MSM7580

THR Processing Timing

Timing Block Diagrams, when CODER and DECODER output data, are shown in the following
figures.
The parallel to serial conversion of the output unit employs a load format and the load point is
at the rising edge of a synchronous signal.
Therefore, input THR signal with respect to SYNCA for CODER with timing of satisfying ts and
th conditions shown in the figure.
For DECODER, THR signal should be input even when through-data is input.
The input timing should satisfy the conditions shown in the following figures.

CODER

Through-data

ADPCM

CODER

S
E
L

SYNCA

SOA

BCLKA

Serial

Parallel

SYNCP

SIP

BCLKP

THR

Latch timing=A

MSB

LSB

MSB

ts=100ns or more

th=100ns or more

PCM side SYNC (SYNCP)

PCM Input (SIP)

Internal Latch timing (A)

Internal Input Data

ADPCM side SYNC (SYNCA)

Through-data Output (SOA)

BCLKA

THR

Through-data

Parallel

Serial

Latch

Note: That data-ship may occur when the rising edge (data load point) of SYNCA and input of

the internal latch timing overlap each other.

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¡ Semiconductor

MSM7580

APPLICATION CIRCUIT

MSM7580GS-K

8 kHz SYNC SIGNAL

(Channel2)

Shift Clock

(Channel1, 2)

(64 kHz to 2048 kHz)

SIP1

SOA1

SOP1

SIA1

THR1

SYNCA1

MUTE1

RES1

SIP2

SOP2

THR2

MUTE2

SYNCP2

PAD/MUTE

BCLKP

GND

LAW

SOA2

SIA2

SYNCA2

RES2

DET2

PDN2

BCLKA

PDN1

SYNCP1

DET1

CODER2

PCM Input

GND

DECODER2

PCM Output

CODER2
ADPCM Output

DECODER2
ADPCM Input

CODER1
ADPCM Output

DECODER1
ADPCM Input

CODER1

PCM Input

DECODER1

PCM Output

8 kHz SYNC SIGNAL

(Channel1)

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¡ Semiconductor

MSM7580

NOTES ON USAGE

(1) Through Mode (CODER Side)

BCLK

PCM side SYNC (SYNCP)

PCM Input (SIP)

Internal Latch Timing

ADPCM side SYNC (SYNCA)

Through-Data Output (SOA)

PCMDATA1

ADPCMDATA0

ADPCMDATA1

ADPCMDATA2

PCMDATA2

PCMDATA3

ADPCMDATA0

ADPCMDATA1

*t1 is the falling edge of the 8th BCLK counted from t0.

(A) When SYNCA rises after t1, PCMDATA1 is output to ADPCMDATA1.
(B) When SYNCA rises before t1, PCMDATA1 is output to ADPCMDATA1.

If SYNCA rises near the t1 and jitter occurs, data slip may occur. Therefore SYNCA should not rise in the range of ±500ns from t1.
Data slip means that data is deleted or the same data is output twice.

(A)

(B)

(2) Through Mode (DECODER Side)

BCLK

ADPCM side SYNC (SYNCA)

ADPCM Input (SIA)

Internal Latch Timing

PCM side SYNC (SYNCP)

Through-Data Output (SOP)

ADPCMDATA1

PCMDATA0

PCMDATA1

PCMDATA2

ADPCMDATA2

ADPCMDATA3

PCMDATA0

PCMDATA1

*t1 is the falling edge of the 8th BCLK counted from t0.

(A) When SYNCA rises after t1, ADPCMDATA1 is output to PCMDATA1.
(B) When SYNCA rises before t1, ADPCMDATA1 is output to PCMDATA1.

If SYNCP rises near the t1 and jitter occurs, data slip may occur. Therefore SYNCA should not rise in the range of ±500ns from t1.
Data slip means that data is deleted or the same data is output twice.

(A)

(B)

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¡ Semiconductor

MSM7580

(3) PCMÆADPCM, ADPCMÆPCM during Transcode

(a) CODER Timing Diagram

MSB

LSB

MSB

LSB

sip

PCM Input Data

PCM Output Data

104.2

119.8

MSB

LSB

MSB

soa

MSB

LSB

MSB

ADPCM Input Data

sia

sop

65.2

119.8

* t5 is the rising edge of SYNCA.

* t7 is the rising edge of SYNCP.

SYNCA

SYNCP

BLCKP

SIP

Internal (1)

Timing (2)

Timing (3)

SOA

SYNCA

BCLKA

SIA

Internal (6)

SYNCP

Timing (4)

Timing (5)

SOP

t4 is the falling edge of the 8th BCLK
counted from the rising edge of SYNCP.

* t6 is the falling edge of the 4th BCLK

counted from the rising edge of SYNCA.

(b) DECODER Timing Diagram

SIP

SYNCP

BCLKP

SOP

SOA

SYNCA

BCLKA

SIA

(1)

8bit

To CODER

From
DECODER

To
DECODER

From CODER

(2)
(5)

(3)
(4)

SYNCA

(6)

8bit

Latch

PLL

Latch

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¡ Semiconductor

MSM7580

In this device, internal operating signals are generated according to the ADPCM side SYNC
(SYNCA) signal.
The timings are shouwn in the figures (a) and (b);
The arithmetic operation of CODER is performed at "A" in the figure (a).
The arithmetic operation of DECODER is performed at "B" in the figure (b).
Therefore, when the conversion delay time Tsip of the CODER is less than t1, ADPCM is output
at the timing of Tsoa.
When Tsip is more than t1, ADPCM is output at the timing of Tsoa + 125ms.
For DECODER, when Tsia<t3 and Tsop<t2, the conversion delay time is Tsop-Tsia.
As mentioned above, a data ship may occur at Tsip=t1 in CODER, and at Tsia=t3 and Tsop=t2
in DECODER.
Therefore, the timings of SYNC signals of both PCM and ADPCM sides should not be set up in
the range about

500nsec of Tsip=t1, Tsia=t3 and Tsop=t2.

For normal operation, SYNC clocks for ADPCM and PCM sides should be continuous at 8 kHz
and synchronized with each other even if their phases are different.

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¡ Semiconductor

MSM7580

(Unit : mm)

PACKAGE DIMENSIONS

Notes for Mounting the Surface Mount Type Package

The SOP, QFP, TSOP, SOJ, QFJ (PLCC), SHP and BGA are surface mount type packages, which
are very susceptible to heat in reflow mounting and humidity absorbed in storage.
Therefore, before you perform reflow mounting, contact Oki's responsible sales person for the
product name, package name, pin number, package code and desired mounting conditions
(reflow method, temperature and times).

SOP28-P-430-1.27-K

Package material
Lead frame material
Pin treatment
Solder plate thickness
Package weight (g)

Epoxy resin
42 alloy
Solder plating
5

mm or more

0.75 TYP.

Mirror finish

NOTICE

The information contained herein can change without notice owing to product and/or
technical improvements. Before using the product, please make sure that the information
being referred to is up-to-date.

The outline of action and examples for application circuits described herein have been
chosen as an explanation for the standard action and performance of the product. When
planning to use the product, please ensure that the external conditions are reflected in the
actual circuit, assembly, and program designs.

When designing your product, please use our product below the specified maximum
ratings and within the specified operating ranges including, but not limited to, operating
voltage, power dissipation, and operating temperature.

Oki assumes no responsibility or liability whatsoever for any failure or unusual or
unexpected operation resulting from misuse, neglect, improper installation, repair, alteration
or accident, improper handling, or unusual physical or electrical stress including, but not
limited to, exposure to parameters beyond the specified maximum ratings or operation
outside the specified operating range.

Neither indemnity against nor license of a third party's industrial and intellectual property
right, etc. is granted by us in connection with the use of the product and/or the information
and drawings contained herein. No responsibility is assumed by us for any infringement
of a third party's right which may result from the use thereof.

The products listed in this document are intended for use in general electronics equipment
for commercial applications (e.g., office automation, communication equipment,
measurement equipment, consumer electronics, etc.). These products are not authorized
for use in any system or application that requires special or enhanced quality and reliability
characteristics nor in any system or application where the failure of such system or
application may result in the loss or damage of property, or death or injury to humans.
Such applications include, but are not limited to, traffic and automotive equipment, safety
devices, aerospace equipment, nuclear power control, medical equipment, and life-support
systems.

Certain products in this document may need government approval before they can be
exported to particular countries. The purchaser assumes the responsibility of determining
the legality of export of these products and will take appropriate and necessary steps at their
own expense for these.

No part of the contents cotained herein may be reprinted or reproduced without our prior
permission.

MS-DOS is a registered trademark of Microsoft Corporation.

Printed in Japan

E2Y0002-29-11

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