ICS9248-64 Datasheet, PDF (13/15 Pages) Integrated Circuit Systems – AMD-K7TM System Clock Chip

ICS9248-64
CPU_STOP# Timing Diagram
CPU_STOP# is an asychronous input to the clock synthesizer. It is used to turn off the CPUCLKs for low power operation.
CPU_STOP# is synchronized by the ICS9248-64. All other clocks will continue to run while the CPUCLKs clocks are
disabled. The CPUCLKs will always be stopped in a low state and start in such a manner that guarantees the high pulse width
is a full pulse. CPUCLK on latency is less than 4 CPUCLKs and CPUCLK off latency is less than 4 CPUCLKs.
INTERNAL
CPUCLK
PCICLK
CPU_STOP#
PCI_STOP# (High)
PD# (High)
CPUCLKT
CPUCLKC
Notes:
1. All timing is referenced to the internal CPUCLK.
2. CPU_STOP# is an asynchronous input and metastable conditions may exist.
This signal is synchronized to the CPUCLKs inside the ICS9248-64.
3. All other clocks continue to run undisturbed including SDRAMR.
4. PD# and PCI_STOP# are shown in a high (true) state.
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