Datasheet

ACPI Devices
Intel
®
Atom™ Processor E6xx Series Datasheet
244
11.8.2.6 Offset 06h: HD0 - Host Data 0
This field is transmitted in the DATA0 field of an SMBus cycle. For block writes, this
register reflects the number of bytes to transfer. This register should be programmed to
a value between 1h (1 bytes) and 20h (32 bytes) for block counts. A count of 00h or
above 20h will result in no transfer and HSTS.CS will be cleared, indicating a failure.
11.8.2.7 Offset 07h: HD1 - Host Data 1
This field is transmitted in the DATA1 field of an SMBus cycle.
11.8.2.8 Offset 20h – 3Fh: HBD – Host Block Data
11.8.3 Overview
The host controller is used to send commands to other SMB devices. It runs off of the
backbone clock, with a minimum SMBCLK frequency the backbone clock divided by 4
(i.e., SMBCLK, at a minimum, is 4 legacy backbone clocks). The frequency to use for
SMBCLK is chosen by programming HCLK.DIV. To ensure proper data capture, the
minimum value to be programmed into this register is 9h (for 33 MHz legacy
backbone), resulting in a frequency roughly equivalent to 1 MHz. Software then sets up
the host controller with an address, command, and for writes, data, and then tells the
controller to start. When the controller has finished transmitting data on writes, or
receiving data on reads, it will generate an SMI#, if enabled.
Table 364. 06h: HD0 - Host Data 0
Size: 8 bit Default: 00h Power Well: Core
Access
PCI Configuration B:D:F
Offset Start:
Offset End:
06h
06h
Bit Range Default Access Acronym Description
07 :00 00h RW CMD Data0: Data Field 0
Table 365. 07h: HD1 - Host Data 1
Size: 8 bit Default: 00h Power Well: Core
Access
PCI Configuration B:D:F
Offset Start:
Offset End:
07h
07h
Bit Range Default Access Acronym Description
07 :00 00h RW CMD Data1: Data Field 1
Table 366. 20h – 3Fh: HBD – Host Block Data
Size: 256 bit Default: 0h Power Well: Core
Access
PCI Configuration B:D:F
Offset Start:
Offset End:
20h
3Fh
Bit Range Default Access Acronym Description
255 :00 0 RW D
Data: This contains block data to be sent on a block write command, or
received block data, on a block read command. Any data received over
32-bytes will be lost.