IDTTM/ICSTM

Programmable System Clock Chip for ATI RS/RD690 K8TM - based Systems

1211B—09/17/09

ICS951464

IDTTM/ICSTM Programmable System Clock Chip for ATI RS/RD690 K8

TM - based Systems

2

Pin Description

PIN #

PIN NAME

TYPE

DESCRIPTION

1

GNDREF

PWR

Ground pin for the REF outputs.

2

VDDREF

PWR

Ref, XTAL power supply, nominal 3.3V

3

X1

IN

Crystal input, Nominally 14.318MHz.

4

X2

OUT

Crystal output, Nominally 14.318MHz

5

VDD48

PWR

Power pin for the 48MHz output.3.3V

6

48MHz_0

OUT

48MHz clock output.

7

48MHz_1

OUT

48MHz clock output.

8

GND48

PWR

Ground pin for the 48MHz outputs

9

SMBCLK

IN

Clock pin of SMBUS circuitry, 5V tolerant

10

SMBDAT

I/O

Data pin of SMBUS circuitry, 5V tolerant

11

RESET_IN#

IN

Real time active low input. When active, SMBus is reset to power up default.

12

SRCCLKT7

OUT

True clock of differential SRC clock pair.

13

SRCCLKC7

OUT

Complement clock of differential SRC clock pair.

14

VDDSRC

PWR

Supply for SRC clocks, 3.3V nominal

15

GNDSRC

PWR

Ground pin for the SRC outputs

16

SRCCLKT6

OUT

True clock of differential SRC clock pair.

17

SRCCLKC6

OUT

Complement clock of differential SRC clock pair.

18

SRCCLKT5

OUT

True clock of differential SRC clock pair.

19

SRCCLKC5

OUT

Complement clock of differential SRC clock pair.

20

SRCCLKT4

OUT

True clock of differential SRC clock pair.

21

SRCCLKC4

OUT

Complement clock of differential SRC clock pair.

22

GNDSRC

PWR

Ground pin for the SRC outputs

23

VDDSRC

PWR

Supply for SRC clocks, 3.3V nominal

24

SRCCLKT2

OUT

True clock of differential SRC clock pair.

25

SRCCLKC2

OUT

Complement clock of differential SRC clock pair.

26

VDDSRC

PWR

Supply for SRC clocks, 3.3V nominal

27

GNDSRC

PWR

Ground pin for the SRC outputs

28

*CLKREQB#

IN

Output enable for PCI Express (SRC) outputs. SMBus selects which outputs are controlled.

0 = enabled, 1 = tri-stated