MEC1404 Datasheet, PDF (239/572 Pages) Microchip Technology – Keyboard and Embedded Controller Products for Notebook PC

MEC140X/1X
TABLE 14-7: EC-ONLY REGISTER SUMMARY
Offset
100h
101h
102h
103h
104h
105h
106h
107h
108h
109h
10Ah
10Bh
Register Name (Mnemonic)
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
Reserved
OS2EC Data EC Byte 0 Register
OS2EC Data EC Byte 1 Register
OS2EC Data EC Byte 2 Register
OS2EC Data EC Byte 3 Register
14.13.1 OS2EC DATA EC BYTE 0 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 ^108h
Bits
Description
Type
Default
Reset
Event
7:0 OS_TO_EC_DATA_BYTE_0
This is byte 0 of the 32-bit OS2EC DATA BYTES[3:0].
R/W
0h
nSYSR
ST
OS2EC DATA BYTES[3:0]
When the CMD bit in the OS STATUS OS Register is cleared to ‘0’, reads by the ACPI_EC from the OS2EC DATA
BYTES[3:0] are aliased to the ACPI-OS DATA BYTES[3:0].
All access to the OS2EC DATA BYTES[3:0] registers should be orderly: Least Significant Byte to Most Significant Byte
when byte access is used.
When the FOUR_BYTE_ACCESS bit in the OS Byte Control Register is cleared to ‘0’, the following access rules apply:
1. Writes to the OS2EC DATA BYTES[3:0] have no effect on the OBF bit in the OS STATUS OS Register.
2. Reads from the OS2EC Data EC Byte 0 Register clears the IBF bit in the OS STATUS OS Register.
3. All reads from OS2EC DATA BYTES[3:1] return 00h without error.
4. Access to OS2EC 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 OS2EC DATA BYTES[3:0] have no effect on the OBF bit in the OS STATUS OS Register.
2. Reads from the OS2EC Data EC Byte 3 Register clears the IBF bit in the OS STATUS OS Register.
 2015 - 2016 Microchip Technology Inc.
DS00001956D-page 239