IDTTM/ICSTM

Programmable System Clock Chip for ATI RS/RD690 K8TM - based Systems

1211B—09/17/09

ICS951464

IDTTM/ICSTM Programmable System Clock Chip for ATI RS/RD690 K8

TM - based Systems

19

RESET_IN# - Assertion (transition from '1' to '0')

The pin is a Schmitt trigger input with debouncing. After it is triggered, REF clocks will wait for two clock cycle to

Asserting RESET_IN pin stops all the outputs including CPU, SRC, ATIG, PCI and USB with the REF[2:0] running.

be power down and re-power up, and SMBus will be reloaded. It will take no more than 2.5mS for the clocks to come

out with correct frequencies and no glitches.

** Deassertion of RESET_IN# (transition from '0' to '1') has NO effect on the clocks.

ensure the RESET_IN is asserted. Then, it will take 3uS for the clocks to stop without glitches. The clock chip will

2.5mS max

3 uS max

2 clock

cycles

RESET_IN#

REF [2:0]

*CLKS