MEC1322 Datasheet, PDF (140/456 Pages) Microchip Technology – Keyboard and Embedded Controller for Notebook PC

MEC1322
10.12.7 OS BYTE CONTROL REGISTER
This register is aliased to the EC Byte Control Register on page 144. No behavioral differences occur due to address
aliasing.
Offset ⁰⁵
Bits
Description
Type
7:1 Reserved
R
0 FOUR_BYTE_ACCESS
R
When this bit is set to ‘1’, the ACPI Embedded Controller Interface
(ACPI-ECI) accesses four bytes through the ACPI-OS DATA
BYTES[3:0].
When this bit is cleared to ‘0’, the ACPI Embedded Controller Inter-
face (ACPI-ECI) accesses one byte through the ACPI OS Data Reg-
ister Byte 0 Register. The corresponds to Legacy Mode described in
Section 10.10, "Description," on page 130.
Default
-
0b
Reset
Event
-
VCC1_R
ESET
Note 1: This bit effects the behavior of the IBF & OBF bits in the
OS STATUS OS Register.
2: See ACPI-OS DATA BYTES[3:0] on page 135, OS2EC
DATA BYTES[3:0] on page 141, and EC2OS DATA
BYTES[3:0] on page 142 for detailed description of
access rules.
Note:
The ACPI_OS access Base Address Register (BAR) should be configured to match the access width
selected by the Four Byte Access bit in the OS Byte Control Register. This BAR in not described in this
chapter.
10.13 EC-Only Registers
The registers listed in the EC-Only Register Summary table are for two instances of the ACPI Embedded Controller
Interface (ACPI-ECI). The addresses of each register listed in this table are defined as a relative offset to the host
“Base Address” defined in the EC-Only Register Base Address Table.
TABLE 10-10: EC-ONLY REGISTER BASE ADDRESS TABLE
Block Instance
Instance
Number
Host
Address Space
Base Address
ACPI-EC
0
EC
32-bit internal
address space
400F_0C00h
ACPI-EC
1
EC
32-bit internal
address space
400F_1000h
The Base Address indicates where the first register can be accessed in a particular address space for a block instance.
TABLE 10-11: EC-ONLY REGISTER SUMMARY
Offset
Register Name (Mnemonic)
100h
101h
102h
103h
104h
105h
106h
EC2OS Data EC Byte 0 Register
EC2OS Data EC Byte 1 Register
EC2OS Data EC Byte 2 Register
EC2OS Data EC Byte 3 Register
EC STATUS Register
EC Byte Control Register
Reserved
DS00001719D-page 140
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