MEC1404 Datasheet, PDF (233/572 Pages) Microchip Technology – Keyboard and Embedded Controller Products for Notebook PC

MEC140X/1X
2. Reads from the ACPI OS Data Register Byte 0 Register clears the OBF bit in the OS STATUS OS Register.
3. All writes to ACPI-OS DATA BYTES[3:1] complete without error but the data are not registered.
4. All reads from ACPI-OS DATA BYTES[3:1] return 00h without error.
5. Access to ACPI-OS DATA BYTES[3:1] has no effect on the IBF & OBF bits in the OS STATUS OS Register.
When the Four Byte Access bit in the OS Byte Control Register is set to ‘1’, the following access rules apply:
1. Writes to the ACPI OS Data Register Byte 3 Register sets the IBF bit in the OS STATUS OS Register.
2. Reads from the ACPI OS Data Register Byte 3 Register clears the OBF bit in the OS STATUS OS Register.
14.12.2 ACPI OS DATA REGISTER BYTE 1 REGISTER
This register is aliased; see ACPI-OS DATA BYTES[3:0] on page 232, OS2EC DATA BYTES[3:0] on page 239, and
EC2OS DATA BYTES[3:0] on page 241 for detailed description of access rules.
Offset ^01h
Bits
Description
7:0 ACPI_OS_DATA_BYTE_1
This is byte 1 of the 32-bit ACPI-OS DATA BYTES[3:0].
Type
R/W
Default
0h
Reset
Event
nSYSR
ST
14.12.3 ACPI OS DATA REGISTER BYTE 2 REGISTER
This register is aliased; see ACPI-OS DATA BYTES[3:0] on page 232, OS2EC DATA BYTES[3:0] on page 239, and
EC2OS DATA BYTES[3:0] on page 241 for detailed description of access rules.
Offset ^02h
Bits
Description
Type
Default
Reset
Event
7:0 ACPI_OS_DATA_BYTE_2
This is byte 2 of the 32-bit ACPI-OS DATA BYTES[3:0].
R/W
0h
nSYSR
ST
14.12.4 ACPI OS DATA REGISTER BYTE 3 REGISTER
This register is aliased; see ACPI-OS DATA BYTES[3:0] on page 232, OS2EC DATA BYTES[3:0] on page 239, and
EC2OS DATA BYTES[3:0] on page 241 for detailed description of access rules.
Offset ^03h
Bits
Description
7:0 ACPI_OS_DATA_BYTE_3
This is byte 3 of the 32-bit ACPI-OS DATA BYTES[3:0].
Type
R/W
Default
0h
Reset
Event
nSYSR
ST
 2015 - 2016 Microchip Technology Inc.
DS00001956D-page 233