E
7.3.5.
82371AB (PIIX4)
151
4/9/97 2:23 PM PIIX4aDS
INTEL CONFIDENTIAL
(until publication date)
PRELIMINARY
SMBHSTADD—SMBUS HOST ADDRESS REGISTER (IO)
I/O Address:
Default Value:
Attribute:
Base + (04h)
00h
Read/Write
This register is transmitted by the SMBus controller host interface in the slave address field of the SMBus
protocol.
Bit
Description
7:1
SMBus Address (SMB_ADDRESS)—R/W.
This field contains the 7-bit address of the targeted
slave device.
0
SMBus Read or Write (SMB_RW)—R/W.
1=Execute a READ command. 0=Execute a WRITE
command.
7.3.6.
SMBHSTDAT0—SMBUS HOST DATA 0 REGISTER (IO)
I/O Address:
Default Value:
Attribute:
Base + (05h)
00h
Read/Write
This register is transmitted by the SMBus controller host interface in the Data 0 field of the SMBus protocol. On
reads, Data 0 bytes are stored here.
Bit
Description
7:0
SMBus Data 0 (SMBD0)—R/W.
This register should be programmed with the value to be
transmitted in the Data 0 field of an SMBus host interface transaction. For a block write command,
the count of the memory block should be stored in this field. The value of this register is loaded into
the block transfer count field. This register must be programmed to a value between 1 and 32 for
block command counts. A count of 0 or a count above 32 will result in unpredictable behavior. For
block reads, the count received from the SMBus device is stored here.
7.3.7.
SMBHSTDAT1—SMBUS HOST DATA 1 REGISTER (IO)
I/O Address:
Default Value:
Attribute:
Base + (06h)
00h
Read/Write
This register is transmitted by the SMBus controller host interface in the Data 1 field of the SMBus protocol. On
reads, Data 1 bytes are stored here.
Bit
Description
7:0
SMBus Data 1 (SMBD1)—R/W.
This register should be programmed with the value to be
transmitted in the Data 1 field of an SMBus host interface transaction.