w83977atg Winbond Electronics Corp America, w83977atg Datasheet - Page 121

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

12.1 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.
For the ACPI software to raise an event to the BIOS software, GBL_RLS, BIOS_EN, and BIOS_STS
bits are involved. BIOS_EN is the enable bit and the BIOS_STS is the status bit. Both are controlled
by the BIOS software. If GBL_RLS is set by the ACPI software and BIOS_EN is set by the BIOS
software, a SMI is raised. Writing a 1 to GBL_RLS sets it to logic 1 and also sets BIOS_STS to logic
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
- 113 -
set
set
set
W83977ATF/W83977ATG
GBL_STS
BIOS_STS
BM_STS
Publication Release Date: May 2006
To SCI Logic
To SMI Logic
To SCI Logic
Revision 0.6