W83977ATF Datasheet, PDF (169/207 Pages) Winbond – WINBOND I/O

W83977ATF
PRELIMINARY
9.0 ACPI REGISTERS FEATURES
The W83977ATF supports both ACPI and legacy power managements. The switch logic of the power
managment block generates an SMI interrupt in the legacy mode and an SCI interrupt in the ACPI
mode. For the legacy mode, the SMI_EN bit is used. If it is set, it routes the power management
events to the SMI interrupt logic. For the ACPI mode, the SCI_EN bit is used. If it is set, it routes
the power management events to the SCI interrupt logic. The SMI_EN bit is located in the
configuration register block of logical device A and the SCI_EN bit is located in the PM1 register
block. See the following figure for illustration.
IRQs
from SCI to SMI
IRQs
PM Timer
from SMI to SCI
Bus Master SCI
Device Idle
Timers
Device Trap
Global STBY
Timer
SMI Logic
0
1
SCI_EN
SCI Logic
SMI_EN
SMI output
Logic
SCI output
Logic
IRQs
Sleep/Wake
State machine
SMI
SCI
WAK_STS
Clock
Control
The SMI interrupt is routed to pin SMI , which is dedicated for the SMI interrupt output. Another way
to output the SMI interrupt is to route to pin IRQSER, which is the signal pin in the Serial IRQ mode.
The SCI interrupt can be routed to pin SCI , which is dedicated for the SCI function. Or it can be
routed to one interrupt request pin, which is selected through CR70 bit3-0 of logical device A.
Another way is to output the SCI interrupt to pin IRQSER if Serial IRQ mode is enabled.
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Publication Release Date:April 1998
Revision 0.53