2

ICS9LPRS464

System Clock Chip for ATI RS/RD600 series chipsets using AMD CPUss

IDTTM/ICSTM

System Clock Chip for ATI RS/RD600 series chipsets using AMD CPUs

1377A—04/07/08

Pin Description

PIN #

PIN NAME

TYPE

DESCRIPTION

1

GNDREF

GND

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 outputs and core. 3.3V

6

48MHz_0

OUT

48MHz clock output.

7

48MHz_1

OUT

48MHz clock output.

8

GND48

GND

Ground pin for the 48MHz outputs

9

SMBCLK

IN

Clock pin of SMBus circuitry, 5V tolerant.

10

SMBDAT

I/O

Data pin for SMBus circuitry, 5V tolerant.

11

RESET_IN#

IN

Real Time falling edge triggered input, When asserted, the part initiates a power

up reset with the SMBus being reset to it's power up values, and all PLL derived

clocks stopped for the duration of Power up Stabilization. REF outputs continue

to run.

12

SRC5T_LPR

OUT

True clock of low power differential SRC clock pair with integrated 33 ohm series

resistor. (no 50ohm shunt resistor to GND needed)

13

SRC5C_LPR

OUT

Complement clock of low power differential SRC clock pair with integrated 33

ohm series resistor. (no 50ohm shunt resistor to GND needed)

14

VDDSRC

PWR

Supply for SRC, 3.3V nominal

15

GNDSRC

GND

Ground pin for the SRC outputs

16

SRC4T_LPR

OUT

True clock of low power differential SRC clock pair with integrated 33 ohm series

resistor. (no 50ohm shunt resistor to GND needed)

17

SRC4C_LPR

OUT

Complement clock of low power differential SRC clock pair with integrated 33

ohm series resistor. (no 50ohm shunt resistor to GND needed)

18

SRC3T_LPR

OUT

True clock of low power differential SRC clock pair with integrated 33 ohm series

resistor. (no 50ohm shunt resistor to GND needed)

19

SRC3C_LPR

OUT

Complement clock of low power differential SRC clock pair with integrated 33

ohm series resistor. (no 50ohm shunt resistor to GND needed)

20

SRC2T_LPR

OUT

True clock of low power differential SRC clock pair with integrated 33 ohm series

resistor. (no 50ohm shunt resistor to GND needed)

21

SRC2C_LPR

OUT

Complement clock of low power differential SRC clock pair with integrated 33

ohm series resistor. (no 50ohm shunt resistor to GND needed)

22

GNDSRC

GND

Ground pin for the SRC outputs

23

VDDSRC

PWR

Supply for SRC, 3.3V nominal

24

SRC1T_LPR

OUT

True clock of low power differential SRC clock pair with integrated 33 ohm series

resistor. (no 50ohm shunt resistor to GND needed)

25

SRC1C_LPR

OUT

Complement clock of low power differential SRC clock pair with integrated 33

ohm series resistor. (no 50ohm shunt resistor to GND needed)

26

VDDSRC

PWR

Supply for SRC, 3.3V nominal

27

GNDSRC

GND

Ground pin for the SRC outputs

28

*CLKREQB#

IN

Programmable Clock Request pin for SRC/ATIG/SB_SRC outputs. If output is

selected for control, then that output is controlled as follows:

0 = Enabled, 1 = Tri-state