©2008 Advanced Micro Devices, Inc. SMBus Module and ACPI Block (Device 20, Function 0)
AMD SB600 Register Reference Manual Proprietary Page 123
2.3.2 SMBus Registers
Register Name Offset Address
SMBusStatus 00h
SMBusSlaveStatus 01h
SMBusControl 02h
SMBusHostCmd 03h
SMBusAddress 04h
SMBusData0 05h
SMBusData1 06h
SMBusBlockData 07h
SMBusSlaveControl 08h
SMBusShadowCmd 09h
SMBusSlaveEvent 0A-0Bh
SlaveData 0C-0Dh
SMBusTiming 0Eh
Note: The SMBus registers are located at the IO memory space base address defined by PCI configuration
register 90-93h
SMBusStatus - RW - 8 bits - [SMBUS:00h]
Field Name Bits Default Description
HostBusy 0 0b This bit indicates the SMBus controller is in the process of
completing a command. When this bit is set, software should
not access any other SMBus registers [Read-only]
SMBusInterrupt 1 0b This bit is set by hardware to indicate the completion of the last
host command. This bit can be cleared by writing an 1 to it.
DeviceErr 2 0b This bit is set by hardware to indicate an error of one of the
following: 1) illegal command field, 2) unclaimed cycle, 3) host
device time-out. This bit can be cleared by writing an 1 to it.
BusCollision 3 0b This bit is set by hardware to indicate SMBus transaction
collision; this bit can be cleared by writing an 1 to it.
Failed 4 0b This bit is set by hardware to indicate a failed bus transaction,
set when SMBusControl.Kill bit is set. This bit is cleared by
writing an 1 to it
Reserved 7:5 000b
SMBusSlaveStatus - RW - 8 bits - [SMBUS:01h]
Field Name Bits Default Description
SlaveBusy 0 0b This bit indicates the SMBus controller slave interface is in the
process of receiving data. Software should not try to access
any other SMBus register when this bit is set. [Read-only]
SlaveInit 1 0b Writing a 1 to this bit will initialize the slave. It is unnecess ary to
write it back to 0. A read from it will always return a 0.
SlaveStatus 2 0b This bit is set by hardware to indicate a slave cycle event match
of the SMBus slave command and SMBus Slave Event match.
This bit can be cleared by writing an 1 to it.
Shadow1Status 3 0b T his bit is set by hardware to indicate a slave cycle address
match of the SMB_Shadow1 port. This bit can be cleared by
writing a 1 to it.
Shadow2Status 4 0b T his bit is set by hardware to indicate a slave cycle address
match of the SMB_Shadow2 port. This bit can be cleared by
writing a 1 to it.
AlertStatus 5 0b This bit is set by hardware to indicate SMBALERT_ signal. This
function is not supported. [Read-only]