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Intel
®
IXP45X and Intel
®
IXP46X Product Line of Network Processors—USB 1.1 Device
Controller
Intel
®
IXP45X and Intel
®
IXP46X Product Line of Network Processors
Developer’s Manual
August 2006
302
Order Number: 306262-004US
8.5.6
UDC Endpoint 4 Control/Status Register
(UDCCS4)
The UDC Endpoint 4 control/status register contains six bits that are used to operate
Endpoint 4, an Isochronous OUT endpoint.
8.5.6.1
Receive FIFO Service (RFS)
The receive FIFO service bit is set if the receive FIFO has one complete data packet in it
and the packet has been error checked by the UDC. A complete packet may be
256 bytes, a short packet, or a zero packet.
UDCCS4[RFS] is not cleared until all data is read from both buffers.
Register Name:
UDCCS3
Hex Offset Address:
0 x C800 B01C
Reset Hex Value:
0 x 00000001
Register
Description:
Register Description: Universal Serial Bus Device Controller Endpoint 3 Control and Status
Register
Access: Read/Write
Bits
31
8
7
6
5
4
3
2
1
0
(Reserved)
TS
P
(Rs
vd)
(Rs
vd)
(Rs
vd)
TUR
FT
F
TP
C
TFS
0
0
0
0
0
0
0
1
Resets (Above)
Register
UDCCS3
Bits
Name
Description
31:8
Reserved for future use.
7
TSP
Transmit short packet (read/write 1 to set).
1 = Short packet ready for transmission.
6
(Reserved). Always reads 0.
5
(Reserved). Always reads 0.
4
(Reserved). Always reads 0.
3
TUR
Transmit FIFO underrun (read/write 1 to clear).
1 = Transmit FIFO experienced an underrun.
2
FTF
Flush Tx FIFO (always read 0/ write a 1 to set).
1 = Flush Contents of TX FIFO.
1
TPC
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.
0
TFS
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.