ADSP-BF535 Blackfin Processor Hardware Reference
14-33
USB Device
USB Endpoint x Address Offset Registers
(USBD_EPADRx)
These registers, represented in
Figure 14-19
, are used to program the
memory buffer offset for data transfers.
They hold the memory offset within the DMA controller’s memory space
for the transfer associated with this endpoint.
DMA transfers occur on 16-byte aligned offsets within the controller’s
memory space (2 KB). As each packet is transferred on the USB, the
USBD_OFFSET
increments by the packet size.
For the USB Endpoint x Address Offset registers and the USB
Endpoint x Buffer Length registers (
USBD_EPLENx
), it is assumed that soft-
ware is keeping track of the original buffer addresses and can calculate the
bytes transferred and the end of valid data based on reading back these
registers at the end of a transfer.
Figure 14-19. USB Endpoint x Address Offset Registers
15 14
13 12
11 10
9
8
7
6
5
4
3
2
1
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
USB Endpoint x Address Offset Registers (USBD_EPADRx)
USBD_OFFSET[10:0]
Memory offset within the
DMA controller’s memory
space
Reset = 0x0000
For MMR
assignments, see
Table 14-4
.
Содержание ADSP-BF535 Blackfin
Страница 80: ...Development Tools 1 26 ADSP BF535 Blackfin Processor Hardware Reference...
Страница 312: ...Working With Memory 6 86 ADSP BF535 Blackfin Processor Hardware Reference...
Страница 332: ...System Interfaces 7 20 ADSP BF535 Blackfin Processor Hardware Reference...
Страница 360: ...Dynamic Power Management Controller 8 28 ADSP BF535 Blackfin Processor Hardware Reference...
Страница 446: ...Beginning and Ending an SPI Transfer 10 40 ADSP BF535 Blackfin Processor Hardware Reference...
Страница 522: ...Timing Examples 11 76 ADSP BF535 Blackfin Processor Hardware Reference...
Страница 562: ...IrDA Support 12 40 ADSP BF535 Blackfin Processor Hardware Reference...
Страница 608: ...PCI I O Issues 13 46 ADSP BF535 Blackfin Processor Hardware Reference...
Страница 672: ...References 14 64 ADSP BF535 Blackfin Processor Hardware Reference...
Страница 810: ...SDRAM Controller SDC 18 86 ADSP BF535 Blackfin Processor Hardware Reference...
Страница 811: ...ADSP BF535 Blackfin Processor Hardware Reference 18 87 External Bus Interface Unit...
Страница 812: ...SDRAM Controller SDC 18 88 ADSP BF535 Blackfin Processor Hardware Reference...
Страница 860: ...DMA Bus Debug Registers 20 30 ADSP BF535 Blackfin Processor Hardware Reference...
Страница 908: ...SDRAM Controller External Bus Interface Unit B 36 ADSP BF535 Blackfin Processor Hardware Reference...