Intel IXP45X Developer's Manual page 766

Intel
Priority Level
2
3
4
(lowest)
Register Name:
0xC800 X008
Hex Offset Address:
Register
Interrupt Identification Register
Description:
Access: See below.
31
Bits
31:8
7:6
5:4
3
2:1
0
® ®
Intel IXP45X and Intel IXP46X Product Line of Network Processors
Developer's Manual
766
® ®
IXP45X and Intel IXP46X Product Line of Network Processors—Universal Asynchronous
Receiver Time out occurred:
It happens in FIFO mode only, when there is data in the receive FIFO but no activity for a
time period.
Transmitter requests data:
In FIFO mode, the transmit FIFO is half or more than half empty.
In non-FIFO mode, THR is read already.
Modem Status:
One or more of the modem input signals has changed state.
(Reserved)
Register
Name
(Reserved)
FIFO Mode Enable Status:
00 = Non-FIFO mode is selected
FIFOES 01 = (Reserved)
10 = (Reserved)
11 = FIFO mode is selected (TRFIFOE = 1)
(Reserved)
Time Out Detected:
TOD 0 = No time out interrupt is pending
1 = Time out interrupt is pending. (FIFO mode only)
Interrupt Source Encoded:
00 = Modem Status (CTS, DSR, RI, DCD modem signals changed state)
IID 01 = Transmit FIFO requests data
10 = Received Data Available
11 = Receive error (Overrun, parity, framing, break, FIFO error)
Interrupt Pending:
IP_N 0 = Interrupt is pending. (Active low)
1 = No interrupt is pending
Interrupt origin
IIR
0x00000001
Reset Hex Value:
IIR
Description
Receiver-Transmitter (UART)
8 7 6 5 4 3 2 1
(Rsvd) IID
August 2006
Order Number: 306262-004US
0