AMD SB600 User Manual
Page 52
©2008 Advanced Micro Devices, Inc.
OCHI USB 1.1 and EHCI USB 2.0 Controllers
AMD SB600 Register Reference Manual
Proprietary
Page 52
Register Name
Offset Address
HcBulkCurrentED 2Ch
HcDoneHead 30h
HcFmInterval 34h
HcFmRemaining 38h
HcFmNumber 3Ch
HcPeriodicStart 40h
HcLSThreshold 44h
HcRhDescriptorA 48h
HcRhDescriptorB 4Ch
HCRhStatus 50h
HcRhPortStatus[1] 54h
… …
HcRhPortStatus[NDP] 54+4*NDP
HcRevision – R - 32 bits - [MEM_Reg : 00h]
Field Name
Bits
Default
Description
REV 7:0
10h
Revision.
This read-only field contains the version of HCI specification.
L 8
1b
Legacy
This read-only field is 1, indicating that the legacy support registers are
present in this HC.
Reserved 31:9
Reserved
HcControl - 32 bits - [MEM_Reg : 04h]
Field Name
Bits
Default
HCD
HC
Description
CBSR 1:0
00b
RW
R
ControlBulkServiceRatio
This specifies the service ratio between Control and
Bulk Eds. Before processing any of the non-periodic
lists, HC must compare the ratio specified with its
internal count on how many nonempty Control Eds
have been processed, in determining whether to
continue serving another Control ED or switching to
Bulk Eds.
CBSR
No. of Control Eds Over Bulk Eds Served
0
1:1
1
2:1
2
3:1
3
4:1
PLE 2
0b
RW
R
PeriodicListEnable
This bit is set to enable the processing of the periodic
list in the next Frame. If cleared by HCD, processing
of the periodic list does not occur after the next SOF.
HC must check this bit before it starts processing the
list.