IDT®

Programmable System Clock Chip for ATI RD790-K8TM Based Systems

1393—01/28/14

9LPRS477C

Programmable System Clock Chip for ATI RD790 - K8TM based Systems

4

General Description

Block Diagram

The 9LPRS477C is a main clock synthesizer chip that provides all clocks required for ATI RD7xx-based

systems.using AMD processors. An SMBus interface allows full control of the device.

REF

CPUKG(1:0)

OSC

14.318MHz

SS

PLL

SB_SRC

(-0.5% DWN SP)

800MHz

SB_SRC(1:0)

100MHz

HTT 100MHz

48MHz_(1:0)

X1

X2

Fixed PLL4

EXACT 48MHz

200MHz

HTT_100C/66

100MHz

SRC6/SATA

HTT 66MHz

ATIG ZDB PLL

SEL_HTT66

SEL_SATA

HTT_100T/66

ATIG(3:0)

SS PLL

SRC(5:0)

SRC ZDB PLL

400 to 900 MHz

PWD @

600MHz/6

SS

PLL

SB_SRC/SRC

PD#

SEL_SATA

SMBCLK

SMBDAT

RESTORE#

Control

Logic

SEL_HTT66

MODE

SEL_DOC

SEL_OC_MODE

Power Groups

VDD

GND

64

3

USB_48 outputs

11, 16

10, 17

SRC differential outputs

25

24

SB_SRC differential outputs

39

42

SRC/SATA differential output

34

28,33

ATIG differential outputs

44

43

Analog, PLL

48

47

CPUKG differential outputs

56

53

HTTCLK output

60

61

REF outputs

Pin Num ber

Description