ICS952003 Datasheet, PDF (16/18 Pages) Integrated Circuit Systems – Programmable Timing Control Hub for P4™ processor

Integrated
Circuit
Systems, Inc.
ICS952003
Preliminary Product Review
PCI_STOP# - Assertion (transition from logic "1" to logic "0")
The impact of asserting the PCI_STOP# signal will be the following. All PCI and stoppable PCI_F clocks will latch low in their
next high to low transition. The PCI_STOP# setup time tsu is 10 ns, for transitions to be recognized by the next rising edge.
Assertion of PCI_STOP# Waveforms
PCI_STOP#
PCI_F 33MHz
PCI 33MHz
tsu
CPU_STOP# - Assertion (transition from logic "1" to logic "0")
The impact of asserting the CPU_STOP# pin is all CPU outputs that are set in the I²C configuration to be stoppable via
assertion of CPU_STOP# are to be stopped after their next transition following the two CPU clock edge sampling as shown.
The final state of the stopped CPU signals is CPUT=Low and CPUC=High.There is to be no change to the output drive current values.
The CPUT will be driven high with a current value equal to (MULTSEL0) X (I REF), the CPUC signal will not be driven.
Assertion of CPU_STOP# Waveforms
CPU_ST OP#
CPUT
CPUC
CPU_STOP# Functionality
CPU_STOP#
1
0
CPUT
Normal
iref * Mult
CPUC
Normal
Float
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