Intel® IXP42X product line and IXC1100 control plane processors—Universal Serial Bus (USB)
v1.1 Device Controller
Intel® IXP42X Product Line of Network Processors and IXC1100 Control Plane Processor
DM September 2006
516 Order Number: 252480-006US
18.5.18 UDC Interrupt Control Register 0 (UICR0)

The UICR0 contains eight control bits to enable/disable interrupt service requests from

data endpoints 0 - 7. All of the UICR0 bits are reset to a 1 so interrupts are not

generated on initial system reset.

18.5.18.1 Interrupt Mask Endpoint x (IMx), Where x is 0 through 7

The UICR0[IMx] bit is used to mask or enable the corresponding endpoint interrupt

request, USIR0[IRx]. When the mask bit is set, the interrupt is masked and the

corresponding bit in the USIR0 register is not allowed to be set.

When the mask bit is cleared and an interruptible condition occurs in the endpoint, the

appropriate interrupt bit is set. Programming the mask bit to a 1 does not affect the

current state of the interrupt bit. It only blocks future 0-to-1 transitions of the interrupt

bit.

Register UDCCS15
Bits Name Description
31:8 Reserved for future use.
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.
4SST
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 1 complete data packet.
Register Name: UICR0
Hex Offset Address: 0 x C800B050 Reset Hex Value: 0x000000FF
Register
Description: Universal Serial Bus Device Controller Interrupt Control Register 0
Access: Read/Write and Read-Only
Bits
31 876543210
(Reserved)
IM7
IM6
IM5
IM4
IM3
IM2
IM1
IM0
X 11111111
Resets (Above)