Регистры H616: OHCI Period Current ED Base

O_HcPeriodCurrentED

9.5.3. OHCI Period Current ED Base - адрес: 0x520041c 0x531041c 0x531141c (смещение: 0x041C)

Хост-контроллер USB2.0: список регистров

31 |•|•|•|•|•|•|•|•|•|•|•|•|•|•|•|•| 16
15 |•|•|•|•|•|•|•|•|•|•|•|•|•|•|•|•| 00

PCED_31_4

Bits 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.

PCED_3_0

Bits 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.

HCD (HC)

Bit fields structure

typedef union o_hcperiodcurrented { struct { unsigned pced_3_0 : 4; unsigned pced_31_4 : 28; } b; unsigned long w; } O_HcPeriodCurrentED