Freescale Semiconductor MPC5200B ユーザーズマニュアル
Host Control (HC) Operational Registers
MPC5200B Users Guide, Rev. 1
Freescale Semiconductor
12-15
12.4.3.6
USB HC Bulk Current Endpoint Descriptor Register—MBAR + 0x102C
The HC Bulk Current Endpoint Descriptor register contains the physical address of the current endpoint of the bulk list. The bulk list is served
in a round-robin fashion, therefore endpoints are ordered according to their insertion into the list.
in a round-robin fashion, therefore endpoints are ordered according to their insertion into the list.
12.4.3.7
USB HC Done Head Register—MBAR + 0x1030
The HC Done Head register contains the physical address of the last completed transfer descriptor that was added to the done queue. In normal
operation, HCD does not need to read this register as its content is periodically written to the HCCA.
operation, HCD does not need to read this register as its content is periodically written to the HCCA.
Table 12-11. USB HC Bulk Head Endpoint Descriptor Register
msb 0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
R
BHED
W
RESET:
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31 lsb
R
BHED
Reserved
W
RESET:
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Bits
Name
Description
0:27
BHED
BulkHeadED—HC traverses the Bulk List starting with the HcBulkHeadED pointer. The
content is loaded from HCCA during the HC initialization.
content is loaded from HCCA during the HC initialization.
28:31
—
Reserved
Table 12-12. USB HC Bulk Current Endpint Descriptor Register
msb 0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
R
BCED
W
RESET:
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31 lsb
R
BCED
Reserved
W
RESET:
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Bits
Name
Description
0:27
BHED
BulkCurrentED—advances to the next ED after HC has served the present ED.
HC continues processing the list from where it left off in the last Frame. When it reaches the end
of the Bulk List, HC checks the HcCommandStatus BulkListFilled.
of the Bulk List, HC checks the HcCommandStatus BulkListFilled.
•
If set, BHED copies HcBulkHeadED content to HcBulkCurrentED and clears bit.
•
If not set, it does nothing.
HCD is only allowed to modify this register when HcControl BulkListEnable is cleared. When
set, HCD only reads the instantaneous value of this register. This is initially set to 0 to indicate
the end of the Bulk List.
set, HCD only reads the instantaneous value of this register. This is initially set to 0 to indicate
the end of the Bulk List.
28:31
—
Reserved