w83977atg Winbond Electronics Corp America, w83977atg Datasheet - Page 120

• Manufacturer Part Number: w83977atg
• Description: W83877tf Plus Kbc, Gp I/o, Wake-up, Fir, Cir, Pb-free
• Manufacturer: Winbond Electronics Corp America

12. ACPI REGISTERS FEATURES
W83977ATF/ATG supports both ACPI and legacy power managements. 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 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.
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.
Global STBY
Device Trap
Device Idle
PM Timer
Timers
Timer
IRQs
from SCI to SMI
from SMI to SCI
Bus Master SCI
IRQs
SCI_EN
1
0
SMI Logic
SCI Logic
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W83977ATF/W83977ATG
IRQs
SMI_EN
State machine
Sleep/Wake
SMI output
SCI output
Logic
Logic
SMI
SCI
WAK_STS
Clock
Control