ADSP-BF535 Blackfin Processor Hardware Reference
14-9
USB Device
For each USB packet transfer, the Memory Interface reports this informa-
tion to the DMA master:
• Current USB endpoint number
• Buffer offset
• Transfer direction
• FIFO status
DMA Master Block
The DMA Master module connects the Memory Interface module to the
DAB bus. The USB DMA channel must win arbitration within 22 DAB
cycles of the assertion of its request.
This module maintains registers to indicate:
• Base address of the USBD module’s access space within system
memory
• Burst count for the current transfer
• Direction for the current transfer
• Status of the DMA module
In normal operation, the device software programs the DMA master with
the base address of a 2 KB block of memory that the USBD module can
use to buffer its data transfers. Transfer offset addresses generated by the
Memory Interface module are concatenated with the DMA base address to
produce a physical address on the DAB. Device software is responsible for
allocating the 2 KB buffer space among all active endpoints.
The DMA address, transfer count, direction, and interrupt status are
available for monitoring.
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...