AMD SB600 User Manual

Page 52

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©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.

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