Intel® IXP42X Product Line of Network Processors and IXC1100 Control Plane Processor
September 2006 DM
Order Number: 252480-006US 487
Universal Serial Bus (USB) v1.1 Device Controller—Intel® IXP42X product line and IXC1100
control plane processors

18.5.3.7 Bit 6 Reserved

Bit 6 is reserved for future use.

18.5.3.8 Transmit Short Packet (TSP)

The software uses the transmit short packet bit to indicate that the last byte of a data

transfer to the FIFO has occurred. This indicates to the UDC that a short packet or zero-

sized packet is ready to transmit.

Software must not set this bit if a 64-byte packet is to be transmitted. When the data

packet is successful transmitted, the UDC clears this bit.

18.5.4 UDC Endpoint 2 Control/Status Register (UDCCS2)

The UDC Endpoint 2 Control/Status Register contains seven bits that are used to

operate endpoint 2, a Bulk OUT endpoint.

Register Name: UDCCS1
Hex Offset Address: 0 x C800B014 Reset Hex Value: 0 x 00000001
Register
Description: Universal Serial Bus Device Controller Endpoint 1 Control and Status Register
Access: Read/Write
Bits
31 876543210
(Reserved)
TSP
(Rsvd)
FST
SST
TUR
FTF
TPC
TFS
X 00000001
Resets (Above)
Register UDCCS1
Bits Name Description
7TSP
Transmit short packet (read/write 1 to set).
1 = Short packet ready for transmission.
6 (Reserved). Always reads 0.
5FST
Force STALL (read/write).
1 = Issue STALL handshakes to IN tokens.
4 SST Sent STALL (read/write 1 to clear).
1 = STALL handshake was sent.
3TUR
Transmit FIFO underrun (read/write 1 to clear)
1 = Transmit FIFO experienced an underrun.
2FTF
Flush Tx FIFO (always read 0/ write a 1 to set).
1 = Flush Contents of TX FIFO
1TPC
Transmit packet complete (read/write 1 to clear).
0 = Error/status bits invalid.
1 = Transmit packet has been sent and error/status bits are valid.
0TFS
Transmit FIFO service (read-only).
0 = Transmit FIFO has no room for new data
1 = Transmit FIFO has room for at least 1 complete data packet