MCF5272VF66J Datasheet, PDF (279/544 Pages) Freescale Semiconductor, Inc – MCF5272 ColdFire® Integrated Microprocessor

Universal Serial Bus (USB)
Table 12-13. EPnCTL Field Descriptions
Bits
Name
Description
1
IN_DONE This bit controls the USB's response to IN tokens from the host. Set at Reset and on an EOT event
and must be cleared by software when the last byte of a transfer has been written to the IN-FIFO. This
bit is then subsequently set by the USB core when an end of transfer (EOT) event occurs, indicating
that the transfer has been completed. An end of transfer (EOT) event is indicated by one of the
following:
a) An IN packet is transmitted that contains less than the maximum number of bytes defined at
endpoint configuration.
b) A zero length IN packet is transmitted. This occurs when the previously transmitted IN packet was
full, and no more data remains in the IN-FIFO. Hence a single zero length packet must be sent to
indicate EOT.
0 CPU has completed writing to the IN-FIFO and transfer is in progress. The USB module sends all
the data in the FIFO, or a zero-length packet when the FIFO is empty.
1 Transfer completed or CPU is busy writing to the IN-FIFO. The USB module only sends
maximum-sized packets or NAK responses if the FIFO contains less data than the maximum
packet size.
0
STALL Force STALL response. Causes the endpoint to return a STALL handshake when polled by either IN
or OUT token by the USB host controller. The STALL handshake causes the endpoint to be halted.
The STALL bit is not valid for isochronous endpoints. This command bit is write-only and always
returns 0 when read.
0 Default
1 Send STALL handshake
MCF5272 ColdFire^® Integrated Microprocessor User’s Manual, Rev. 3
Freescale Semiconductor
12-21