IDTTM Frequency Generator with 200MHz Differential CPU Clocks

0542

K—03/23/16

ICS950812

Frequency Generator with 200MHz Differential CPU Clocks

22

Pin #

Name

0

1

PWD

Bit 7

X

-

Spread Spectrum Bit7

RW

-

-

X

Bit 6

X

-

Spread Spectrum Bit6

RW

-

-

X

Bit 5

X

-

Spread Spectrum Bit5

RW

-

-

X

Bit 4

X

-

Spread Spectrum Bit4

RW

-

-

X

Bit 3

X

-

Spread Spectrum Bit3

RW

-

-

X

Bit 2

X

-

Spread Spectrum Bit2

RW

-

-

X

Bit 1

X

-

Spread Spectrum Bit1

RW

-

-

X

Bit 0

X

-

Spread Spectrum Bit0

RW

-

-

X

Affected Pin

Note: Please utilize software utility provided by ICS Application Engineering to configure spread spectrum. Incorrect spread

percentage may cause system failure.

BYTE

13

Control Function

Type

Bit Control

Pin #

Name

0

1

PWD

Bit 7

X

-

(Reserved)

RW

-

-

X

Bit 6

X

-

(Reserved)

RW

-

-

X

Bit 5

X

-

Spread Spectrum Bit13

RW

-

-

X

Bit 4

X

-

Spread Spectrum Bit12

RW

-

-

X

Bit 3

X

-

Spread Spectrum Bit11

RW

-

-

X

Bit 2

X

-

Spread Spectrum Bit10

RW

-

-

X

Bit 1

X

-

Spread Spectrum Bit9

RW

-

-

X

Bit 0

X

-

Spread Spectrum Bit8

RW

-

-

X

BYTE

14

Affected Pin

Control Function

Note: Please utilize software utility provided by ICS Application Engineering to configure spread spectrum. Incorrect spread

percentage may cause system failure.

Bit Control

Type

Note: See table 8 for Byte 11-14 default information

Spread Spectrum Enable Procedure

Step 1: Power-up ---- Latched inputs, FS(5:0), set frequency per Hardware default on board. SS is off.

BIOS program set IIC Byte0, bit7 to 1, SS will be enable Spread. Note that Byte 10,

bit 7 is default to 0. This allows all setup to be controlled by the Frequency Select

Tables, 1 and 2.

Step 3: To set up Linear programming and SS% adjust using Byte 11 through 14, the BIOS must

set

Byte 10, bit 7 to a 1. This will enable access to Byte 11 and 12, M/N linear programming

and Byte 13 and 14, Spread Spectrum % adjust.

Step 2: After power up, SS% can be changed to the fixed selections shown in Frequency Table 2. This

is achieved by Writing to Byte 4, bit 6/7 (FS5:4) and/or Byte 0 (FS3), The data written

to these bytes will overwrite the existing contents and switch to the desired selection.