1 transmit fifo service (tfs), 2 transmit packet complete (tpc), Udccs1/6/11 bit definitions -27 – Intel PXA255 User Manual
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Intel® PXA255 Processor Developer’s Manual
12-27
USB Device Controller
12.6.4
UDC Endpoint x Control/Status Register (UDCCS1/6/11)
, contains 6 bits that are used to operate endpoint(x), a Bulk
IN endpoint).
12.6.4.1
Transmit FIFO Service (TFS)
The transmit FIFO service bit is active if one or fewer data packets remain in the transmit FIFO.
TFS is cleared when two complete packets of data remain in the FIFO. A complete packet of data is
signified by loading 64 bytes of data or by setting UDCCSx[TSP].
12.6.4.2
Transmit Packet Complete (TPC)
The transmit packet complete bit is set by the UDC when an entire packet is sent to the host. When
this bit is set, the IRx bit in the appropriate UDC status/interrupt register is set if transmit interrupts
are enabled. This bit can be used to validate the other status/error bits in the endpoint(x) control/
status register. The UDCCSx[TPC] bit is cleared by writing a 1 to it. This clears the interrupt
source for the IRx bit in the appropriate UDC status/interrupt register, but the IRx bit must also be
cleared.
Table 12-15. UDCCS1/6/11 Bit Definitions
0x 4060_0014
0x 4060_0028
0x 4060_003C
UDCCS1
UDCCS6
UDCCS11
USB Device Controller
Bit
31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10 9
8
7
6
5
4
3
2
1
0
reserved
TSP
reser
ved
FST
SST
TU
R
FTF
TPC
TFS
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
0
0
0
0
0
0
0
1
Bit
Name
Description
31:8 —
reserved
7
TSP
Transmit short packet
1 = Short packet ready for transmission.
6
—
reserved
5
FST
Force STALL
1 = Issue STALL handshakes to IN tokens.
4
SST
Sent STALL
1 = STALL handshake was sent.
3
TUR
Transmit FIFO underrun
1 = Transmit FIFO experienced an underrun.
2
FTF
Flush Tx FIFO
1 = Flush Contents of TX FIFO
1
TPC
Transmit packet complete
0 = Error/status bits invalid.
1 = Transmit packet has been sent and error/status bits are valid.
0
TFS
Transmit FIFO service
0 = Transmit FIFO has no room for new data
1 = Transmit FIFO has room for at least 1 complete data packet