8

Integrated

Circuit

Systems, Inc.

ICS951411

0891E—03/07/05

SMBus Table: Frequency Select Register

Pin #

Name

Control Function

Type0

1

PWD

Bit 7

FS Source

Latched Input or SMBus

Frequency Select

RW

Latched

Inputs

SMBus

0

Bit 6

SS_EN

Spread Enable

RW

OFF

ON

0

Bit 5

Reserved

Reserved

RW

Reserved

Reserved

X

Bit 4

CK410#

CPU Freq Select Bit 4

RW

Latched

Bit 3

CPU FS3

CPU SS_EN

RW

0

Bit 2

CPU FS_C

CPU Freq Select Bit 2

RW

Latched

Bit 1

CPU FS_B

CPU Freq Select Bit 1

RW

Latched

Bit 0

CPU FS_A

CPU Freq Select Bit 0

RW

Latched

NOTE: Byte 0 bit 6 and Byte 0 bit 3 must BOTH be '1' to enable spread for the PCI $ CPU clocks.

Byte 5 bit 4 must be set to 1 to enable spread for the SRC & ATIGCLKS.

SMBus Table: Output Control Register

Pin #

Name

Control Function

Type0

1

PWD

Bit 7

PCICLK0

Output Enable

RW

Disable

Enable

1

Bit 6

CPUCLK2

Output Enable

RW

Disable

Enable

1

Bit 5

USB_48MHz

Output Enable

RW

Disable

Enable

1

Bit 4

REF0

Output Enable

RW

Disable

Enable

1

Bit 3

REF1

Output Enable

RW

Disable

Enable

1

Bit 2

REF2

Output Enable

RW

Disable

Enable

1

Bit 1

CPUCLK0

Output Enable

RW

Disable

Enable

1

Bit 0

CPUCLK1

Output Enable

RW

Disable

Enable

1

SMBus Table: CLKREQB# Output Control Register

Pin #

Name

Control Function

Type0

1

PWD

Bit 7

REQBSRC7

CLKREQB# Controls

SRC7

RW

Does not

control

Controls

0

Bit 6

REQBSRC6

CLKREQB# Controls

SRC6

RW

Does not

control

Controls

0

Bit 5

REQBSRC5

CLKREQB# Controls

SRC5

RW

Does not

control

Controls

0

Bit 4

REQBSRC4

CLKREQB# Controls

SRC4

RW

Does not

control

Controls

0

Bit 3

REQBSRC3

CLKREQB# Controls

SRC3

RW

Does not

control

Controls

0

Bit 2

Reserved

Reserved

RW

Reserved

Reserved

X

Bit 1

Reserved

Reserved

RW

Reserved

Reserved

X

Bit 0

REQBSRC0

CLKREQB# Controls

SRC0

RW

Does not

control

Controls

0

NOTE: CPU0_Stop_En (Byte2, bit 2) only exists in devices with REV ID = 2 or higher

-

34,33

18,19

22,23

24,25

-

43,42

Byte 2

12,13

16,17

54

53

52

47,46

Byte 1

50

41,40

4

-

See Table 1: CPU

Frequency Selection Table

-

-

-

-

Byte 0

-

-

-