w83977atf Winbond Electronics Corp America, w83977atf Datasheet - Page 170

• Manufacturer Part Number: w83977atf
• Description: Winbond I/o
• Manufacturer: Winbond Electronics Corp America

9.1 SMI to SCI/SCI to SMI and Bus Master
The following figure illustrates the process of generating an interrupt from SMI to SCI or from SCI to
For the BIOS software to raise an event to the ACPI software, BIOS_RLS, GBL_EN, and GBL_STS
bits are involved. GBL_EN is the enable bit and the GBL_STS is the status bit. Both are controlled
by the ACPI software. If BIOS_RLS is set by the BIOS software and GBL_EN is set by the ACPI
software, an SCI interrupt is raised. Writing a 1 to BIOS_RLS sets it to logic 1 and also sets
GBL_STS to logic 1. Writing a 0 to BIOS_RLS has no effect. Writing a 1 to GBL_STS clears it to
logic 0 and also clears BIOS_RLS to logic 0. Writing a 0 to GBL_STS has no effect.
SMI .
from SMI to SCI
from SCI to SMI
Bus Master SCI
: Status bit
: Enable bit
BM_CNTPL
BIOS_RLS
GBL_RLS
BIOS_EN
BM_RLD
GBL_EN
clear
clear
clear
set
set
set
-114 -
GBL_STS
BIOS_STS
BM_STS
Publication Release Date:April 1998
To SCI Logic
To SMI Logic
To SCI Logic
W83977ATF
PRELIMINARY
Revision 0.53