W83877TF/W83877TG
Publication Release Date: May 2006
-109- Revision 0.7
11.3 ACPI Registers Features
W83877TF/TG supports both the ACPI and legacy power management's. The switch logic of the
power management 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 from the SMI interrupt logic to the SMI output pin. For the ACPI mode, the SCI_EN bit is used.
If it is set, it route the power management events to the SCI interrupt logic. The SMI_EN bit is located
in the CR3A register and the SCI_EN bit is located in the PM1 register block. See the following figure
for illustration.
PM Timer
Device Idle
Timers
Device Trap
Timer
SMI Logic
SMI_EN
SMI output
Logic
SCI output
Logic
Sleep/Wake
State machine
WAK_STS
Clock
Control
SCI
SMI
SCI Logic
Global STBY
SCI events
0
1
SCI_EN
SMI events
IRQs
IRQs
IRQs
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 is routed to pin
SCI , which is dedicated for the SCI function. The other way to output the
SCI interrupt is to route to one interrupt request signal pin IRQA~H, which is selected through CR31
bit[7:4]. Another way is output the SCI interrupt is to route to pin IRQSER.
