Probe State; Stop Grant State - AMD AX1800DMT3C - Athlon XP 1.53 GHz Processor Datasheet

AMD Athlon™ XP Processor Model 6 Data Sheet

Probe State

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Preliminary Information
The Stop Grant state is also entered for the S1, Powered On
Suspend, system sleep state based on a write to the SLP_TYP
and SLP_EN fields in the ACPI-defined Power Management 1
control register in the Southbridge. During the S1 Sleep state,
system software ensures no bus master or probe activity occurs.
The Southbridge deasserts STPCLK# and brings the processor
out of the S1 Stop Grant state when any enabled resume event
occurs.
The Probe state is entered when the Northbridge connects the
AMD Athlon system bus to probe the processor (for example, to
snoop the processor caches) when the processor is in the Halt or
Stop Grant state. When in the Probe state, the processor
responds to a probe cycle in the same manner as when it is in
the Working state. When the probe has been serviced, the
processor returns to the same state as when it entered the
Probe state (Halt or Stop Grant state). When probe activity is
completed the processor only returns to a low-power state after
the Northbridge disconnects the AMD Athlon system bus again.
Power Management
24309E—March 2002
Chapter 4