Host Control (HC) Operational Registers
MPC5200B Users Guide, Rev. 1
Freescale Semiconductor 12-13
USB HC Bulk Current Endpint Descriptor Register (0x102C)
USB HC Done Head Register (0x1030)
12.4.3.1 USB HC HCCA Register—MBAR + 0x1018
The HC HCCA register contains the physical address of the Host Controller Communication Area. HCD determines alignment restrictions
by writing all 1s to HcHCCA and reading the HcHCCA content. Alignment is evaluated by examining the number of 0s in the lower order
bits. Minimum alignment is 256Bytes. Bits 0 through 7 must always return 0 when read. This area holds control structures and the interrupt
table, which are accessed by both the HC and HCD.
12.4.3.2 USB HC Period Current Endpoint Descriptor Register —MBAR + 0x101C
The HC Period Current Endpoint Descriptor (ED) register contains the physical address of the current isochronous or interrupt endpoint
descriptor.

Table12-7. USB HC HCCA Register

msb 012345678 9 101112131415
RHCCA
W
RESET:000000000 0 0 000 0 0
16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 lsb
RHCCA Reserved
W
RESET:000000000 0 0 000 0 0
Bits Name Description
0:23 HCCA Host Controller Communication Area—base address.
24:31 — Reserved

Table12-8. USB HC Period Current Endpoint Descriptor Register

msb 012345678 9 101112131415
RPCED
W
RESET:000000000 0 0 000 0 0
16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 lsb
RPCED Reserved
W
RESET:000000000 0 0 000 0 0
Bits Name Description
0:27 PCED PeriodCurrentED—HC uses this field to point to the head of one of the Periodic lists, which is
processed in the current Frame. HC updates register content after a periodic ED is processed.
HCD may read the content in determining which ED is currently being processed at the time
of reading.
28:31 — Reserved