W83194R-39/-39A

100MHZ 3-DIMM CLOCK

Publication Release Date: May 1998

- 1 - Revision 0.20

1.0 GENERAL DESCRIPTION

The W83194R-39/-39A is a Clock Synthesizer which provides all clocks required for high-speed RISC
or CISC microprocessor such as Intel Pentium II. W83194R-39 provides eight different frequency of
CPU and PCI clocks and W83194R-39A provides sixteen CPU/PCI frequencies which are externally
selectable with smooth transitions. W83194R-39/-39A also provides 13 SDRAM clocks controlled by
the none-delay buffer_in pin.

The W83194R-39/-39A accepts a 14.318 MHz reference crystal as its input and runs on a 3.3V
supply. Spread spectrum built in at

¡Ó

0.5% or

¡Ó

0.25% to reduce EMI. Programmable stopping

individual clock outputs and frequency selection through I

C interface. The device meets the

Pentium power-up stabilization, which requires CPU and PCI clocks be stable within 2 ms after
power-up. It is not recommend to use the dual function pin for the slots(ISA, PCI, CPU, DIMM). The
add on cards may have a pull up or pull down.

High drive six PCI and thirteen SDRAM CLOCK outputs typically provide greater than 1 V /ns slew
rate into 30 pF loads. Two CPU CLOCK outputs typically provide better than 1 V /ns slew rate into 20
pF loads as maintaining 50

¡Ó

5% duty cycle. The fixed frequency outputs as REF, 24MHz, and 48

MHz provide better than 0.5V /ns slew rate.

2.0 PRODUCT FEATURES

Supports Pentium

II CPU with I

2 CPU clocks (one free-running CPU clock)

13 SDRAM clocks for 3 DIMs

6 PCI synchronous clocks

One IOAPIC clock for multiprocessor support

Optional single or mixed supply:

(Vddq1=Vddq2 = Vddq3 = Vddq4 = VddL1 =VddL2= 3.3V) or (Vddq1= Vddq2 = Vddq3=Vddq4 =

3.3V, VddL1 = VdqL2 = 2.5V)

< 250ps skew among CPU and SDRAM clocks

< 250ps skew among PCI clocks

< 5ns propagation delay SDRAM from buffer input

Skew from CPU(earlier) to PCI clock -1 to 4ns, center 2.6ns.

Smooth frequency switch with selections from 50 MHz to 133 MHz CPU

C 2-Wire serial interface and I

C read back

W83194R-39/-39A

PRELIMINARY

Publication Release Date: May 1998

- 2 - Revision 0.20

¡Ó

0.25% or

¡Ó

0.5% spread spectrum function to reduce EMI

Programmable registers to enable/stop each output and select modes

(mode as Tri-state or Normal )

2ms power up clock stable time

MODE pin for power Management

One 48 MHz for USB & one 24 MHz for super I/O

48-pin SSOP package

3.0 BLOCK DIAGRAM

PLL2

XTAL
OSC

Spread
Spectrum

PLL1

LATCH

POR

STOP

1/2

Control

Logic

Config.

Reg.

STOP

PCI
Clock
Divider

48MHz

24MHz

IOAPIC

REF(0:1)

CPUCLK_F

CPUCLK1

SDRAM(0:12)

PCICLK(0:4)

PCICLK_F

Xin

Xout

BUFFER IN

FS(0:2)*

MODE*

CPU_STOP#

PCI_STOP#

SDATA*

SDCLK*

PLL2

XTAL
OSC

Spread
Spectrum

PLL1

LATCH

POR

STOP

1/2

Control

Logic

Config.

Reg.

STOP

PCI
Clock
Divider

48MHz

24MHz

IOAPIC

REF(0:1)

CPUCLK_F

CPUCLK1

SDRAM(0:11)

PCICLK(0:4)

PCICLK_F

Xin

Xout

BUFFER IN

FS(0:3)*

MODE*

CPU_STOP#

PCI_STOP#

SDATA*

SDCLK*

SDRAM12

W83194R-39

W83194R-39A

W83194R-39/-39A

PRELIMINARY

Publication Release Date: May 1998

- 3 - Revision 0.20

4.0 PIN CONFIGURATION

48
47
46
45

43
42
41
40
39
38
37
36
35
34

33
32
31
30
29
28
27
26
25

1
2
3
4

6
7

9
10
11
12
13
14
15

17
18
19
20
21
22
23
24

Vddq1

PCI_STOP#/REF0

Vss
Xin

Xout

Vddq2

PCICLK_F/MODE*

PCICLK0/FS3*

Vss

PCICLK1

PCICLK2
PCICLK3
PCICLK4

Vddq2

BUFFER IN

Vss

SDRAM11

SDRAM10

Vddq3

SDRAM 9
SDRAM 8

Vss

SDATA
SDCLK

VddL1

IOAPIC

REF1/FS2*

Vss

CPUCLK_F

CPUCLK1
VddL2

CPU_STOP#
SDRAM12

Vss
SDRAM 0

SDRAM 1

SDRAM 2

Vddq3

SDRAM 3
Vss
SDRAM 4
SDRAM 5

SDRAM 6
SDRAM 7
Vddq4

Vddq3

48MHz/FS0*
24MHz/FS1*

(W83194R-39A )

5.0 PIN DESCRIPTION

IN - Input

OUT - Output

I/O - Bi-directional Pin

# - Active Low

* - Internal 250k

pull-up

W83194R-39/-39A

PRELIMINARY

Publication Release Date: May 1998

- 4 - Revision 0.20

5.1 Crystal I/O

SYMBOL

PIN

I/O

FUNCTION

Xin

Crystal input with internal loading capacitors and
feedback resistors.

Xout

OUT

Crystal output at 14.318MHz nominally.

5.2 CPU, SDRAM, PCI, IOAPIC Clock Outputs

SYMBOL

PIN

I/O

FUNCTION

CPUCLK_F

OUT

Free running CPU clock. Not affected by
CPU_STOP#

CPUCLK1

OUT

Low skew (< 250ps) clock outputs for host
frequencies such as CPU, Chipset and Cache.
Powered by VddL2. Low if CPU_STOP# is low.

CPU_STOP#

This asynchronous input halts CPUCLK1,IOAPIC &
SDRAM(0:12) at logic

"0"

level when driven low.

IOAPIC

OUT

High drive buffered output of the crystal, and is
powered by VddL1.

SDRAM [ 0:12]

17,18,20,21,28

,29,31,32,34,

35,37,38,40

OUT

SDRAM clock outputs. Fanout buffer outputs from
BUFFER IN pin.(Controlled by chipset)

PCICLK_F/

*MODE

I/O

Free running PCI clock during normal operation.

Latched Input. Mode=1, Pin 2 is REF0; Mode=0,
Pin2 is PCI_STOP#

PCICLK0/*FS3
(W83194R-39A)

I/O

Low skew (< 250ps) PCI clock outputs.

Latched input for FS3 at initial power up for H/W
selecting the output frequency of CPU, SDRAM and
PCI clocks.

PCICLK [ 0:4 ]

(W83194R-39)

8,10,11,12,13

OUT

Low skew (< 250ps) PCI clock outputs. Synchronous
to CPU clocks with 1-48ns skew(CPU early).

BUFFER IN

Inputs to fanout for SDRAM outputs.

SDRAM [ 0: 11 ]

17,18,20,21,
28,29,31,32,

34,35,37,38

Synchronous DRAM DIMs clocks which have the
same frequency as CPU clocks

W83194R-39/-39A

PRELIMINARY

Publication Release Date: May 1998

- 5 - Revision 0.20

5.3 I

C Control Interface

SYMBOL

PIN

I/O

FUNCTION

SDATA

I/O

Serial data of I

C 2-wire control interface with internal

pull-up resistor.

SDCLK

Serial clock of I

C 2-wire control interface with

internal pull-up resistor.

5.4 Fixed Frequency Outputs

SYMBOL

PIN

I/O

FUNCTION

REF0 / PCI_STOP#

I/O

14.318MHz reference clock. This REF output is the
stronger buffer for ISA bus loads.

Halt PCICLK(0:4) clocks at logic 0 level, when input
low (In mobile mode. MODE=0)

REF1 / *FS2

I/O

14.318MHz reference clock.

Latched input for FS2 at initial power up for H/W
selecting the output frequency of CPU, SDRAM and
PCI clocks.

24MHz / *FS1

I/O

24MHz output clock.

Latched input for FS1 at initial power up for H/W
selecting the output frequency of CPU, SDRAM and
PCI clocks.

48MHz / *FS0

I/O

48MHz output for USB during normal operation.

Latched input for FS0 at initial power up for H/W
selecting the output frequency of CPU, SDRAM and
PCI clocks.

5.5 Power Pins

SYMBOL

PIN

FUNCTION

Vddq1

Power supply for Ref [0:1] crystal and core logic.

VddL1

Power supply for IOAPIC output, either 2.5V or 3.3V.

VddL2

Power supply for CPUCLK[0:3], either 2.5V or 3.3V.

Vddq2

6, 14

Power supply for PCICLK_F, PCICLK[0:4], 3.3V.

Vddq3

19, 30, 36

Power supply for SDRAM[0:12], and CPU PLL core,
nominal 3.3V.

Vddq4

Power for 24 & 48MHz output buffers and fixed PLL
core.

Vss

3,9,16,22,33,39,45 Circuit Ground.

W83194R-39/-39A

PRELIMINARY

Publication Release Date: May 1998

- 6 - Revision 0.20

6.0 FREQUENCY SELECTION

6.1 Frequency table of W83194R-39

FS2

FS1

FS0

CPU,SDRAM (MHz)

PCI (MHz)

REF,IOAPIC (MHz)

25(CPU/2)

14.318

37.5(CPU/2)

14.318

83.3

41.65(CPU/2)

14.318

66.8

33.4(CPU/2)

14.318

103

34.3(CPU/3)

14.318

112

37.33(CPU/3)

14.318

133

33.25(CPU/4)

14.318

100.2

33.3(CPU/3)

14.318

6.2 Frequency table of W83194R-39A

FS3=0

CPU,SDRAM (MHz)

PCI (MHz)

REF,IOAPIC

FS2

FS1

FS0

(MHz)

124

41.33(CPU/3)

14.318

37.5(CPU/2)

14.318

83.3

41.65(CPU/2)

14.318

66.8

33.4(CPU/2)

14.318

103

34.3(CPU/3)

14.318

112

37.33(CPU/3)

14.318

133

44.33(CPU/3)

14.318

100.3

33.3(CPU/3)

14.318

FS3=1

CPU,SDRAM (MHz)

PCI (MHz)

REF,IOAPIC

FS2

FS1

FS0

(MHz)

120

40.00(CPU/3)

14.318

115

38.33(CPU/3)

14.318

110

36.67(CPU/3)

14.318

105

35.00(CPU/3)

14.318

140

35.00(CPU/4)

14.318

150

37.50(CPU/4)

14.318

124

31.00(CPU/4)

14.318

133

33.25(CPU/4)

14.318

W83194R-39/-39A

PRELIMINARY

Publication Release Date: May 1998

- 8 - Revision 0.20

8.0 FUNTION DESCRIPTION

8.1 POWER MANAGEMENT FUNCTIONS

All clocks can be individually enabled or disabled via the 2-wire control interface. On power up,
external circuitry should allow 3 ms for the VCO

to stabilize prior to enabling clock outputs to

assure correct pulse widths. When MODE=0, pins 15 and 46 are inputs (PCI_STOP#),
(CPU_STOP#), when MODE=1, these functions are not available. A particular clock could be
enabled as both the 2-wire serial control interface and one of these pins indicate that it should be
enable.

The W83194R-39/-39Amay be disabled in the low state according to the following table in order to
reduce power consumption. All clocks are stopped in the low state, but maintain a valid high period
on transitions from running to stop. The CPU and PCI clocks transform between running and stop by
waiting for one positive edge on PCICLK_F followed by negative edge on the clock of interest, after
which high levels of the output are either enabled or disabled.

CPU_STOP#

PCI_STOP#

CPUCLK1,

IOAPIC &

SDRAM 0:12

PCI

OTHER CLKs

XTAL & VCOs

LOW

RUNNING

LOW

RUNNING

LOW

RUNNING

8.2 2-WIRE I

C CONTROL INTERFACE

The clock generator is a slave I

C component which can be

ead back

the data stored in the

latches for verification. All proceeding bytes must be sent to change one of the control bytes. The 2-
wire control interface allows each clock output individually enabled or disabled. On power up, the
W83194R-39/-39Ainitializes with default register settings, and then it

optional to use the 2-wire

control interface.

The SDATA signal only changes when the SDCLK signal is low, and is stable when SDCLK is high
during normal data transfer. There are only two exceptions. One is a high-to-low transition on
SDATA while SDCLK is high used to indicate the beginning of a data transfer cycle. The other is a
low-to-high transition on SDATA while SDCLK is high used to indicate the end of a data transfer
cycle. Data is always sent as complete 8-bit bytes followed by an acknowledge generated.

Byte writing starts with a

tart

condition followed by 7-bit slave address and a write command bit

[1101 0010], command code checking [0000 0000], and byte count checking. After successful
reception of each byte, an

cknowledge

(low) on the SDATA wire will be generated by the clock

chip. Controller can start to write to internal I

C registers after the string of data. The sequence

order is as follows:

W83194R-39/-39A

PRELIMINARY

Publication Release Date: May 1998

- 9 - Revision 0.20

Bytes sequence order for I

C controller :

Clock Address

A(6:0) & R/W

Ack

8 bits dummy

Command code

Ack

8 bits dummy

Byte count

Ack

Byte0,1,2...

until Stop

Set R/W to 1 when

ead back

the data sequence is as follows :

Clock Address

A(6:0) & R/W

Ack

Byte 0

Ack

Byte2, 3, 4...

until Stop

Byte 1

8.3 SERIAL CONTROL REGISTERS

The Pin column lists the affected pin number and the @PowerUp column gives the default state at
true power up. "Command Code" byte and "Byte Count" byte must be sent following the
acknowledge of the Address Byte. Although the data (bits) in these two bytes are considered "don't
care", they must be sent and will be acknowledge. After that, the below described sequence
(Register 0, Register 1, Register 2, ....) will be valid and acknowledged.

8.3.1 Register 0: CPU Frequency Select Register (default = 0)

Bit

@PowerUp

Pin

Description

0 =

¡Ó

0.25% Spread Spectrum Modulation

1 =

¡Ó

0.5% Spread Spectrum Modulation

SSEL2 (for frequency table selection by software via I

SSEL1 (for frequency table selection by software via I

SSEL0 (for frequency table selection by software via I

0 = Selection by hardware

1 = Selection by software I

C - Bit 6:4

SSEL3 (for frequency table selection by software via I

0 = Normal

1 = Spread Spectrum enabled

0 = Running

1 = Tristate all outputs

Note : The frequency table selected by software via I

C is the same as the hardware setting

frequency table.

W83194R-39/-39A

PRELIMINARY

Publication Release Date: May 1998

- 10 - Revision 0.20

Function Table

Function

Outputs

Description

CPU

PCI

SDRAM

REF

IOAPIC

Tri-State

Hi-Z

Normal

see table

CPU

14.318

8.3.2 Register 1 : CPU , 48/24 MHz Clock Register (1 = enable, 0 = Stopped)

Bit

@PowerUp

Pin

Description

Latched FS2#

Reserved

SDRAM12 (Active / Inactive)

Reserved

CPUCLK1 (Active / Inactive)

CPUCLK_F (Active / Inactive)

W83194R-39/-39A

PRELIMINARY

Publication Release Date: May 1998

- 11 - Revision 0.20

8.3.3 Register 2: PCI Clock Register (1 = enable, 0 = Stopped)

Bit

@PowerUp

Pin

Description

Reserved

PCICLK_F (Active / Inactive)

Reserved

PCICLK4 (Active / Inactive)

PCICLK3 (Active / Inactive)

PCICLK2 (Active / Inactive)

PCICLk1 (Active / Inactive)

PCICLK0 (Active / Inactive)

8.3.4 Register 3: SDRAM Clock Register ( 1 = enable, 0 = Stopped )

Bit

@PowerUp

Pin

Description

Reserved

48MHz (Active / Inactive)

24MHz (Active / Inactive)

Reserved

21,20,18,17

SDRAM(8:11) (Active / Inactive)

32,31,29,28

SDRAM(4:7) (Active / Inactive)

38,37,35,34

SDRAM(0:3) (Active / Inactive)

W83194R-39/-39A

PRELIMINARY

Publication Release Date: May 1998

- 12 - Revision 0.20

8.3.5 Register 4: Reserved Register (1 = enable, 0 = Stopped)

Bit

@PowerUp

Pin

Description

Reserved

Latched FS1#

Reserved

8.3.6 Register 5: Peripheral Control (1 = enable, 0 = Stopped)

Bit

@PowerUp

Pin

Description

Reserved

IOAPIC (Active / Inactive)

Reserved

REF1 (Active / Inactive)

REF0 (Active / Inactive)

NOTE:

1. Inactive means outputs are held LOW and are disabled from switching.

2. Latched Frequency Selects(FS#) will be inverted logic load of the input frequency select pin

conditions.

W83194R-39/-39A

PRELIMINARY

Publication Release Date: May 1998

- 13 - Revision 0.20

9.0 SPECIFICATIONS

9.1 ABSOLUTE MAXIMUM RATINGS

Stresses greater than those listed in this table may cause permanent damage to the device.
Precautions should be taken to avoid application of any voltage higher than the maximum rated
voltages to this circuit. Maximum conditions for extended periods may affect reliability. Unused
inputs must always be tied to an appropriate logic voltage level (Ground or Vdd).

Symbol

Parameter

Rating

Vdd , V

Voltage on any pin with respect to GND

- 0.5 V to + 7.0 V

STG

Storage Temperature

- 65

C to + 150

Ambient Temperature

- 55

C to + 125

Operating Temperature

C to + 70

9.2 AC CHARACTERISTICS

Vdd = Vddq3 = 3.3V

5 %, Vddq2 = VddL1=VddL2 = 2.375V~2.9V , T

= 0

C to +70

Parameter

Symbol

Min

Typ

Max

Units

Test Conditions

Output Duty Cycle

Measured at 1.5V

CPU/SDRAM to PCI Offset

OFF

15 pF Load Measured at 1.5V

Skew (CPU-CPU), (PCI-
PCI), (SDRAM-SDRAM)

SKEW

250

15 pF Load Measured at 1.5V

CPU/SDRAM

Cycle to Cycle Jitter

CCJ

¡Ó

250

CPU/SDRAM

Absolute Jitter

500

Jitter Spectrum 20 dB

Bandwidth from Center

500

KHz

Output Rise (0.4V ~ 2.0V)

& Fall (2.0V ~0.4V) Time

TLH

THL

0.4

1.6

15 pF Load on CPU and PCI
outputs

Overshoot/Undershoot

Beyond Power Rails

over

0.7

1.5

at source of 8 inch PCB

run to 15 pF load

Ring Back Exclusion

RBE

0.7

2.1

Ring Back must not enter this
range.

W83194R-39/-39A

PRELIMINARY

Publication Release Date: May 1998

- 14 - Revision 0.20

9.3 DC CHARACTERISTICS

Vdd = Vddq3 = 3.3V

5 %, Vddq2 = VddL1=VddL2 = 2.375V~2.9V , T

= 0

C to +70

Parameter

Symbol

Min

Typ

Max

Units

Test Conditions

Input Low Voltage

0.8

Input High Voltage

2.0

Input Low Current

-66

Input High Current

Output Low Voltage

= 4 mA

0.4

All outputs

Output High Voltage

= 4mA

2.4

All outputs using 3.3V power

Tri-State leakage Current

Ioz

Dynamic Supply Current

for Vdd + Vddq3

dd3

CPU = 66.6 MHz

PCI = 33.3 Mhz with load

Dynamic Supply Current

for Vddq2 + Vddq2b

dd2

Same as above

CPU Stop Current

for Vdd + Vddq3

CPUS3

Same as above

CPU Stop Current

for Vddq2 + Vddq2b

CPUS2

Same as above

PCI Stop Current

for Vdd + Vddq3

PD3

W83194R-39/-39A

PRELIMINARY

Publication Release Date: May 1998

- 15 - Revision 0.20

9.4 BUFFER CHARACTERISTICS

9.4.1 TYPE 1 BUFFER FOR CPU CLOCK

Parameter

Symbol

Min

Typ

Max

Units

Test Conditions

Pull-Up Current Min

OH(min)

-27

Vout = 1.0 V

Pull-Up Current Max

OH(max)

-27

Vout = 2.0V

Pull-Down Current Min

OL(min)

Vout = 1.2 V

Pull-Down Current Max

OL(max)

Vout = 0.3 V

Rise/Fall Time Min
Between 0.4 V and 2.0 V

RF(min)

0.4

10pF Load

Rise/Fall Time Max
Between 0.4 V and 2.0 V

RF(max)

1.6

20pF Load

9.4.2 TYPE 2 BUFFER FOR IOAPIC

Parameter

Symbol

Min

Typ

Max

Units

Test Conditions

Pull-Up Current Min

OH(min)

Vout = 1.4 V

Pull-Up Current Max

OH(max)

-29

Vout = 2.7 V

Pull-Down Current Min

OL(min)

Vout = 1.0 V

Pull-Down Current Max

OL(max)

Vout = 0.2 V

Rise/Fall Time Min
Between 0.7 V and 1.7 V

RF(min)

0.4

10pF Load

Rise/Fall Time Max
Between 0.7 V and 1.7 V

RF(max)

1.8

20pF Load

W83194R-39/-39A

PRELIMINARY

Publication Release Date: May 1998

- 16 - Revision 0.20

9.4.3 TYPE 3 BUFFER FOR REF1, 24MHZ, 48MHZ

Parameter

Symbol

Min

Typ

Max

Units

Test Conditions

Pull-Up Current Min

OH(min)

-29

Vout = 1.0 V

Pull-Up Current Max

OH(max)

-23

Vout = 3.135V

Pull-Down Current Min

OL(min)

Vout = 1.95 V

Pull-Down Current Max

OL(max)

Vout = 0.4 V

Rise/Fall Time Min
Between 0.8 V and 2.0 V

RF(min)

1.0

10pF Load

Rise/Fall Time Max

Between 0.8 V and 2.0 V

RF(max)

4.0

20pF Load

9.4.4 TYPE 4 BUFFER FOR SDRAM (0:12)

Parameter

Symbol

Min

Typ

Max

Units

Test Conditions

Pull-Up Current Min

OH(min)

Vout = 1.65 V

Pull-Up Current Max

OH(max)

-46

Vout = 3.135 V

Pull-Down Current Min

OL(min)

Vout = 1.65 V

Pull-Down Current Max

OL(max)

Vout = 0.4 V

Rise/Fall Time Min
Between 0.8 V and 2.0 V

RF(min)

0.5

20pF Load

Rise/Fall Time Max

Between 0.8 V and 2.0 V

RF(max)

1.3

30pF Load

9.4.5 TYPE 5 BUFFER FOR PCICLK(0:4,F)

Parameter

Symbol

Min

Typ

Max

Units

Test Conditions

Pull-Up Current Min

OH(min)

-33

Vout = 1.0 V

Pull-Up Current Max

OH(max)

-33

Vout = 3.135 V

Pull-Down Current Min

OL(min)

Vout = 1.95 V

Pull-Down Current Max

OL(max)

Vout = 0.4 V

Rise/Fall Time Min
Between 0.8 V and 2.0 V

RF(min)

0.5

15pF Load

Rise/Fall Time Max

Between 0.8 V and 2.0 V

RF(max)

2.0

30pF Load

W83194R-39/-39A

PRELIMINARY

Publication Release Date: May 1998

- 17 - Revision 0.20

10.0 POWER MANAGEMENT TIMING

10.1 CPU_STOP# Timing Diagram

CPUCLK

(Internal)

PCICLK

(Internal)

PCICLK_F

CPU_STOP#

CPUCLK[0:3]

SDRAM

For synchronous Chipset, CPU_STOP# pin is an asynchronous

active low

input pin used to stop

the CPU clocks for low power operation. This pin is asserted synchronously by the external control
logic at the rising edge of free running PCI clock(PCICLK_F). All other clocks will continue to run
while the CPU clocks are stopped. The CPU clocks will always be stopped in a low state and resume
output with full pulse width. In this case, CPU

locks on latency

is less than 4 CPU clocks and

locks off latency

is less then 4 CPU clocks.

10.2 PCI_STOP# Timing Diagram

CPUCLK

(Internal)

PCICLK

(Internal)

PCICLK_F

PCI_STOP#

PCICLK[0:5]

For synchronous Chipset, PCI_STOP# pin is an asynchronous

ctive low

input pin used to stop

the PCICLK [0:4] for low power operation. This pin is asserted synchronously by the external control
logic at the rising edge of free running PCI clock(PCICLK_F). All other clocks will continue to run
while the PCI clocks are stopped. The PCI clocks will always be stopped in a low state and resume
output with full pulse width. In this case, PCI

locks on latency

is less than 2 PCI clocks and

locks off latency

is less then 2 PCI clocks.

W83194R-39/-39A

PRELIMINARY

Publication Release Date: May 1998

- 18 - Revision 0.20

11.0 OPERATION OF DUAL FUCTION PINS

Pins 2, 7, 8, 25, and 26 are dual function pins and are used for selecting different functions in this
device (see Pin description). During power up, these pins are in input mode (see Fig1), therefore,
and are considered input select pins. When Vdd reaches 2.5V, the logic level that is present on these
pins are latched into their appropriate internal registers. Once the correct information are properly
latched, these pins will change into output pins and will be pulled low by default. At the end of the
power up timer (within 3 ms) outputs starts to toggle at the specified frequency.

Within 3ms

Input

Output

Output tri-state

Output pull-low

2.5V

Output tri-state

Output pull-low

#7 PCICLK_F/MODE

#46 REF1/FS2

#25 24/FS1

#26 48/FS0

All other clocks

Vdd

Each of these pins are a large pull-up resistor ( 250 k

@3.3V ) inside. The default state will be logic

1, but the internal pull-up resistor may be too large when long traces or heavy load appear on these
dual function pins. Under these conditions, an external 10 k

resistor is recommended to be

connected to Vdd if logic 1 is expected. Otherwise, the direct connection to ground if a logic 0 is
desired. The 10 k

resistor should be place before the serious terminating resistor. Note that these

logic will only be latched at initial power on.

If optional EMI reducing capacitor are needed, they should be placed as close to the series
terminating resistor as possible and after the series terminating resistor. These capacitor has typical
values ranging from 4.7pF to 22pF.

W83194R-39/-39A

PRELIMINARY

Publication Release Date: May 1998

- 20 - Revision 0.20

13.0 ORDERING INFORMATION

Part Number

Package Type

Production Flow

W83194R-39/-39A

48 PIN SSOP

Commercial, 0

C to +70

14.0 HOW TO READ THE TOP MARKING

W83194R-39
28051234
814GBB

W83194R-39A
28051234
814GBB

1st line: Winbond logo and the type number: W83194R-39/-39A

2nd line: Tracking code 2 8051234
2: wafers manufactured in Winbond FAB 2

8051234: wafer production series lot number

3rd line: Tracking code 814 G B B

814: packages made in '98, week 14
G: assembly house ID; A means ASE, S means SPIL, G means GR

BB: IC revision

All the trade marks of products and companies mentioned in this data sheet belong to
their respective owners.

W83194R-39/-39A

PRELIMINARY

Publication Release Date: May 1998

- 21 - Revision 0.20

15.0 PACKAGE DRAWING AND DIMENSIONS

Headquarters

No. 4, Creation Rd. III

Science-Based Industrial Park

Hsinchu, Taiwan

TEL: 886-35-770066

FAX: 886-35-789467

www: http://www.winbond.com.tw/

Taipei Office

11F, No. 115, Sec. 3, Min-Sheng East Rd.

Taipei, Taiwan

TEL: 886-2-7190505

FAX: 886-2-7197502

TLX: 16485 WINTPE

Winbond Electronics (H.K.) Ltd.

Rm. 803, World Trade Square, Tower II

123 Hoi Bun Rd., Kwun Tong

Kowloon, Hong Kong

TEL: 852-27516023-7

FAX: 852-27552064

Winbond Electronics
(North America) Corp.

2730 Orchard Parkway

San Jose, CA 95134 U.S.A.

TEL: 1-408-9436666

FAX: 1-408-9436668

Please note that all data and specifications are subject to change without notice. All the
trade marks of products and companies mentioned in this data sheet belong to their
respective owners.

These products are not designed for use in life support appliances, devices, or systems
where malfunction of these products can reasonably be expected to result in personal
injury. Winbond customers using or selling these products for use in such applications
do so at their own risk and agree to fully indemnify Winbond for any damages resulting
from such improper use or sale.

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