Owners manual

Interfaces
H3 Datasheet(Revision1.2) Copyright© 2015 Allwinner Technology Co.,Ltd.All Rights Reserved. Page 510
8.5.2.6.8. HcPeriodCurrentED Register(Default Value: 0x00000000)
Offset: 0x41c
Register Name: HcPeriodCurrentED(PCED)
Bit
Read/Write
Default/Hex
Description
HCD
HC
31:4
R
R/W
0x0
PCED[31:4]
This is used by HC to point to the head of one of the Periodec list which
will be processed in the current Frame. The content of this register is
updated by HC after a periodic ED has been processed. HCD may read the
content in determining which ED is currently being processed at the time
of reading.
3:0
R
R
0x0
PCED[3:0]
Because the general TD length is 16 bytes, the memory structure for the
TD must be aligned to a 16-byte boundary. So the lower bits in the PCED,
through bit 0 to bit 3 must be zero in this field.
8.5.2.6.9. HcControlHeadED Register(Default Value: 0x00000000)
Offset: 0x420
Register Name: HcControlHeadED[CHED]
Bit
Read/Write
Default/Hex
Description
HCD
HC
31:4
R/W
R
0x0
EHCD[31:4]
The HcControlHeadED register contains the physical address of the first
Endpoint Descriptor of the Control list. HC traverse the Control list
starting with the HcControlHeadED pointer. The content is loaded from
HCCA during the initialization of HC.
3:0
R
R
0x0
EHCD[3:0]
Because the general TD length is 16 bytes, the memory structure for the
TD must be aligned to a 16-byte boundary. So the lower bits in the PCED,
through bit 0 to bit 3 must be zero in this field.
8.5.2.6.10. HcControlCurrentED Register(Default Value: 0x00000000)
Offset: 0x424
Register Name: HcControlCurrentED[CCED]
Bit
Read/Write
Default/Hex
Description
HCD
HC
31:4
R/W
R/W
0x0
CCED[31:4]
The pointer is advanced to the next ED after serving the present one. HC
will continue processing the list from where it left off in the last Frame.
When it reaches the end of the Control list, HC checks the
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