ADSP-BF535 Blackfin Processor Hardware Reference
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USB Device
The following sections show example flows for control transfers without a
data phase and with a data phase.
Control Transfer, No Data Phase
A control transfer with no data phase consists of these steps:
1. At initialization time, device software unmasks the
USBD_SETUP
interrupt on the control endpoint(s).
2. Device initializes the
USBD_EPADRx
and
USBD_EPLENx
registers to
point to storage buffers.
3. Device initializes the
USBD_EPCFGx
registers for OUT direction,
USBD_TYP
= 00,
USBD_DIR
= 0 (OUT direction). The
USBD_MAX
field
is programmed to match the endpoint’s maximum packet size. The
USBD_ARM
bit is set to 1.
4. Monitor the
USBD_SETUP
interrupt.
5. On receipt of a
USBD_SETUP
interrupt, read the setup packet from
the memory buffer and decode the command. If the command is
valid, execute it.
6. To complete the command, a status packet must be returned to the
USB host. For a transfer with no data phase, this is an IN transfer
of 0 bytes, or a STALL handshake. If the command completes suc-
cessfully, set the endpoint registers (
USBD_EPCFGx
,
USBD_EPLENx
) for
a 0 byte IN transfer, and set the
USBD_ARM
bit to 1. If the command
does not complete successfully, set the
USBD_EPxSTALL
bit in the
USBD_CTRL
register.
Summary of Contents for ADSP-BF535 Blackfin
Page 80: ...Development Tools 1 26 ADSP BF535 Blackfin Processor Hardware Reference...
Page 312: ...Working With Memory 6 86 ADSP BF535 Blackfin Processor Hardware Reference...
Page 332: ...System Interfaces 7 20 ADSP BF535 Blackfin Processor Hardware Reference...
Page 360: ...Dynamic Power Management Controller 8 28 ADSP BF535 Blackfin Processor Hardware Reference...
Page 446: ...Beginning and Ending an SPI Transfer 10 40 ADSP BF535 Blackfin Processor Hardware Reference...
Page 522: ...Timing Examples 11 76 ADSP BF535 Blackfin Processor Hardware Reference...
Page 562: ...IrDA Support 12 40 ADSP BF535 Blackfin Processor Hardware Reference...
Page 608: ...PCI I O Issues 13 46 ADSP BF535 Blackfin Processor Hardware Reference...
Page 672: ...References 14 64 ADSP BF535 Blackfin Processor Hardware Reference...
Page 810: ...SDRAM Controller SDC 18 86 ADSP BF535 Blackfin Processor Hardware Reference...
Page 811: ...ADSP BF535 Blackfin Processor Hardware Reference 18 87 External Bus Interface Unit...
Page 812: ...SDRAM Controller SDC 18 88 ADSP BF535 Blackfin Processor Hardware Reference...
Page 860: ...DMA Bus Debug Registers 20 30 ADSP BF535 Blackfin Processor Hardware Reference...