©2008 Advanced Micro Devices, Inc. SMBus Module and ACPI Block (Device 20, Function 0)
AMD SB600 Register Reference Manual Proprietary Page 182
2.3.5 ASF SM bus Host Interface Registers
The ASF SM bus host register block is resident in the Io space whose base defined at offset 58h/59h of
config space.
Register Name Offset Address
HostStatus 00h
HostControl 02h
HostCommand 03h
SlaveAddress 04h
Data0 05h
Data1 06h
Data 07h
PEC 08h
ASFStatus 0Ah
StatusMask0 0Bh
StatusMask1 0Ch
SlaveControl 0Dh
RemoteCtrlAdr 0Eh
SensorAdr 0Fh
HostStatus – R - 8 bits - [ASF_IO: 00h]
Field Name Bits Default Description
HostBusy 0 0b 0 – SM bus Host is idle
1 – SM bus Host is busy
Reserve 1 0b
DevError 2 0b 0: Slave device behave correctly
1: No ACK or Slave device responses incorrectly
BusCollision 3 0b 0: No bus collision
1: Bus collision
PECError 4 0b 0: No CRC error
1: CRC error happens
Reserve 6:5 00b
LastByte 7 0b 0: Last byte has not received
1: Last byte has received
HostControl – RW - 8 bits - [ASF_IO: 02h]
Field Name Bits Default Description
Reserved 0 0b
KillHost 1 0b 0 – Enable SM master
1 – Reset SM master
Protocol 4:2 000b 000: Quick
001: Byte
010: Byte Data
011: Word Data
100: Process call
101: Block
PECAppend 5 0b 0: No PEC append
1: Automatic PEC append. ASF HC calculates CRC code and
append to the tail of the data packets.
Start 6 0b WO:
0: Always read 0 on reads
1: Writing 1 to initiate the command