Causes Of Host And Global Resets - Intel 6 SERIES CHIPSET - DATASHEET 01-2011 Datasheet

Functional Description
Table 5-39. Causes of Host and Global Resets
Write of 0Eh to CF9h Register when Global Reset Bit=0b
Write of 06h to CF9h Register when Global Reset Bit=0b
Write of 06h or 0Eh to CF9h Register when Global Reset
Bit=1b
SYS_RESET# Asserted and CF9h Bit 3 = 0
SYS_RESET# Asserted and CF9h Bit 3 = 1
SMBus Slave Message received for Reset with Power
Cycle
SMBus Slave Message received for Reset without Power
Cycle
TCO Watchdog Timer reaches zero two times
Power Failure: PWROK signal or SYS_PWROK signal
goes inactive or RSMRST# asserts
Special shutdown cycle from processor causes CF9h-
like PLTRST# and CF9h Global Reset Bit = 1
Special shutdown cycle from processor causes CF9h-
like PLTRST# and CF9h Bit 3 = 1
Special shutdown cycle from processor causes CF9h-
like PLTRST# and CF9h Global Reset Bit = 0
®
Intel Management Engine Triggered Host Reset
without power cycle
Intel Management Engine Triggered Host Reset with
power cycle
Intel Management Engine Triggered Global Reset
Intel Management Engine Initiated Host Reset with
power down
PLTRST# Entry Time-out
Intel Management Engine Watchdog Timer
Power Management Watchdog Timer
PROCPWRGD Stuck Low
NOTES:
1. Trigger will result in Global Reset with power cycle if the acknowledge message is not
received by the PCH.
2. The PCH does not send warning message to processor, reset occurs without delay.
3. The PCH waits for enabled wake event to complete reset.
4. The PCH allowed to drop this type of reset request if received while the system is in S3/S4/
S5.
The PCH must not drop this type of reset request if received while system is in a
software-entered S3/S4/S5 state. However, the PCH is allowed to perform the reset
without executing the RESET_WARN protocol in these states.
Datasheet
Trigger
Host Reset Host Reset
without with Power
Power Cycle Cycle
No Yes
Yes No
No No
Yes No
No Yes
No Yes
Yes No
Yes No
No No
No No
No Yes
Yes No
Yes No
No Yes
No No
No Yes (Note 3)
No No
No Yes (Note 4)
No Yes (Note 4)
No No
Global Reset
with Power
Cycle
No (Note 1)
No (Note 1)
Yes
No (Note 1)
No (Note 1)
No (Note 1)
No (Note 1)
No (Note 1)
Yes (Note 2)
Yes
No (Note 2)
No (Note 1)
No (Note 1)
No (Note 1)
Yes
No (Note 1)
Yes
No (Note 1)
No (Note 1)
Yes
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