AMD SB600 - Manual (Page 68)

©2008 Advanced Micro Devices, Inc. OCHI USB 1.1 and EHCI USB 2.0 Controllers
AMD SB600 Register Reference Manual Proprietary Page 68
2.2.2.3 Programming Interface
The following modification is needed for the HcRevision register:
Table 2-1 HcRevision Register
HcRevision - 32 bits
Field Name Bits Reset HCD HC Description
Revision 7:0 10h R R This read-only field contains the BCD representation
of the version of the HCI specification that is
implemented by this HC. For example, a value of 11h
corresponds to version 1.1. All of the HC
implementations that are compliant with this
specification will have a value of 10h.
Legacy 8 1b R R This read-only field is 1 to indicate that the legacy
support registers are present in this HC.
Reserved 31:9 Reserved
Legacy Support Registers
Four operational registers are used to provide the legacy support. Each of these registers is located on a 32-
bit boundary. The offset of these registers is relative to the base address of the Host Controller operational
registers with HceControl located at offset 100h.
Table 2-2 Legacy Support Registers
Offset Register Description
100h HceControl Used to enable and control the emulation hardware and report various status
information.
104h HceInput The emulation side of the legacy Input Buffer register.
108h HceOutput The emulation side of the legacy Output Buffer register where the keyboard and
mouse data is to be written by software.
10Ch HceStatus The emulation side of the legacy Status register.
Three of the operational registers (HceStatus, HceInput, HceOutput) are accessible at I/O address 60h and
64h when emulation is enabled. Reads and writes to the registers using I/O addresses have side effects as
outlined in
Table 2-3 .
Table 2-3 Emulated Registers
I/O
Address Cycle Type Register Contents
Accessed/Modified Side Effects
60h IN HceOutput IN from port 60h will set OutputFull in
HceStatus to 0
60h OUT HceInput OUT to port 60h will set InputFull to 1 and
CmdData to 0 in HceStatus.
64h IN HceStatus IN from port 64h returns current value of
HceStatus with no other side effect.
64h OUT HceInput OUT to port 64h will set InputFull to 0 and
CmdData in HceStatus to 1.
HceInput Register