9LPRS477D

PROGRAMMABLE SYSTEM CLOCK CHIP FOR ATI RD790-K8TM BASED SYSTEMS

IDT®

PROGRAMMABLE SYSTEM CLOCK CHIP FOR ATI RD790-K8TM BASED SYSTEMS

2

9LPRS477D

REV C 010715

Pin Descriptions

PIN #

PIN NAME

PIN TYPE

DESCRIPTION

1

**SEL_DOC/48MHz _1

I/O

SEl_DOC: latched input to s elect pin functionality

1 = DOC input.

0 = SRCCLK5

/ 48MHz cloc k output.

2

**SEL_CPU1#/48MHz_0

I/O

SEL_CPU1 latched input to selec t pin functionality

1 = SRCCLK7

0 = CPUKG1

/ 48MHz cloc k output.

3

GND48

GND

Ground pin for the 48MHz outputs

4SMBCLK

IN

Clock pin of SMBus c ircuitry, 5V tolerant.

5SMBDAT

I/O

Data pin for SMBus circuitry, 5V tolerant.

6

**DOC_0/SRC5C_LPRS

OUT

Dynamic Over Clock ing pin: real time frequency selection 0: Normal; 1: Frequency will transition to a

preprogrammed value in the I2c.

/ Complement clock of low power differential SRC c lock pair. (no 50ohm shunt resistor to GND and no 33 ohm

s eries resistor needed

7

**DOC_1/SRC5T_LPRS

OUT

Dynamic Over Clock ing pin: real time frequency selection 0: Normal; 1: Frequency will transition to a

preprogrammed value in the I2c.

/ True clock of low power differential SRC clock pair. (no 50ohm shunt resistor to GND and no 33 ohm series

resistor needed

8

SRC4C_LPRS

OUT

Complement clock of low power differential SouthBridge SRC clock pair. (no 50ohm shunt resistor to GND and no

33 ohm series resistor needed

9

SRC4T_LPRS

OUT

T rue cloc k of low power differential SRC clock pair. (no 50ohm s hunt res istor to GND and no 33 ohm s eries

resistor needed

10

GNDSRC

GND

Ground pin for the SRC outputs

11

VDDSRC

PWR

Supply for SRC core, 3.3V nominal

12

SRC3C_LPRS

OUT

Complement clock of low power differential SouthBridge SRC clock pair. (no 50ohm shunt resistor to GND and no

33 ohm series resistor needed

13

SRC3T_LPRS

OUT

T rue cloc k of low power differential SRC clock pair. (no 50ohm s hunt res istor to GND and no 33 ohm s eries

resistor needed

14

SRC2C_LPRS

OUT

Complement clock of low power differential SouthBridge SRC clock pair. (no 50ohm shunt resistor to GND and no

33 ohm series resistor needed

15

SRC2T_LPRS

OUT

T rue cloc k of low power differential SRC clock pair. (no 50ohm s hunt res istor to GND and no 33 ohm s eries

resistor needed

16

VDDSRC

PWR

Supply for SRC core, 3.3V nominal

17

GNDSRC

GND

Ground pin for the SRC outputs

18

SRC1C_LPRS

OUT

Complement clock of low power differential SouthBridge SRC clock pair. (no 50ohm shunt resistor to GND and no

33 ohm series resistor needed

19

SRC1T_LPRS

OUT

T rue cloc k of low power differential SRC clock pair. (no 50ohm s hunt res istor to GND and no 33 ohm s eries

resistor needed

20

SRC0C_LPRS

OUT

Complement clock of low power differential SouthBridge SRC clock pair. (no 50ohm shunt resistor to GND and no

33 ohm series resistor needed

21

SRC0T_LPRS

OUT

T rue cloc k of low power differential SRC clock pair. (no 50ohm s hunt res istor to GND and no 33 ohm s eries

resistor needed

22

SB_SRC1C_LPRS

OUT

Complement clock of low power differential SouthBridge SRC clock pair. (no 50ohm shunt resistor to GND and no

33 ohm series resistor needed

23

SB_SRC1T_LPRS

OUT

T rue cloc k of low power differential SouthBridge SRC clock pair. (no 50ohm shunt res istor to GND and no 33 ohm

s eries resistor needed

24

GNDSB_SRC

GND

Ground pin for the SB_SRC outputs

25

VDDSB_SRC

PWR

Supply for SRC core, 3.3V nominal

26

SB_SRC0C_LPRS

OUT

Complement clock of low power differential SouthBridge SRC clock pair. (no 50ohm shunt resistor to GND and no

33 ohm series resistor needed

27

SB_SRC0T_LPRS

OUT

T rue cloc k of low power differential SouthBridge SRC clock pair. (no 50ohm shunt res istor to GND and no 33 ohm

s eries resistor needed

28

GNDATIG

GND

Ground pin for the ATIG outputs

29

ATIG3C_LPRS

OUT

Complementary cloc k of low-power differential pus h-pull PCI-Express pair with integrated series resistor. (no

50ohm s hunt res istor to GND and no 33 ohm s eries resistor needed)

30

ATIG3T_LPRS

OUT

T rue cloc k of low-power differential push-pull PCI-Express pair with integrated series resistor. (no 50ohm shunt

resistor to GND and no 33 ohm series resistor needed)

31

ATIG2C_LPRS

OUT

Complementary cloc k of low-power differential pus h-pull PCI-Express pair with integrated series resistor. (no

50ohm s hunt res istor to GND and no 33 ohm s eries resistor needed)

32

ATIG2T_LPRS

OUT

T rue cloc k of low-power differential push-pull PCI-Express pair with integrated series resistor. (no 50ohm shunt

resistor to GND and no 33 ohm series resistor needed)