ADSP-BF535 Blackfin Processor Hardware Reference
14-45
USB Device
The UDC module gives software access to the endpoint buffers via the
USBD_EPBUF
register. The following steps must be followed to ensure
proper download.
1. Verify that the UDC is ready to accept configuration data by read-
ing the
USBD_RDY
bit from the
USB_EPBUF
register.
2. Write the first/next byte of the endpoint buffer to the
USBD_EPDOWN
field of the
USBD_EPBUF
register.
This action causes the
USBD_RDY
bit to change to 0. The
USD_CFG
bit
remains at 1 until the download process is complete.
3. Wait for the
USBD_RDY
bit to return to 1.
Depending on the clock frequency of the PAB, the wait can be 30
or more clock periods.
4. Go back to step 2.
After all bytes have been written, read back the
USBD_CFG
bit from
the
USBD_EPBUF
register and verify that it has switched from 1 to 0,
indicating that the UDC has received all the bytes expected.
For each logical endpoint, you must download 5 bytes of data start-
ing with the most significant byte. See the UDC Endpoint Buffer
register in
Figure 14-21 on page 14-37
for more information about
the UDC register format.
For endpoint 0, program the configuration, interface, and alternate
values to 0 in the UDC Endpoint Buffer register.
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...