Intel® IXP42X product line and IXC1100 control plane processors—Universal Asynchronous
Receiver Transceiver (UART)
Intel® IXP42X Product Line of Network Processors and IXC1100 Control Plane Processor
DM September 2006
356 Order Number: 252480-006US
10.4.13 Infrared Selection Register

The Slow Infrared (SIR) Interface can be used in conjunction with a standard UART to

support two-way, wireless communications using infrared radiation. It provides a

transmit encoder and receive decoder to support a physical link that conforms to the

Infrared Data Association Serial Infrared Specification.

In the IXP42X product line and IXC1100 control plane processors, infrared mode is not

supported. The reason for including this register in the address map and register

description section is so software can ensure that this mode is never enabled.

Register SPR
Bits Name Description
31:8 (Reserved)
7 SCR No effect on UART functionality
Register Name: ISR
Hex Offset Address: 0xC800 0020 Reset Hex Value: 0x00000000
Register
Description: Infrared Selection Register
Access: Read/Write.
31 876543210
(Reserved)
DMAE
UUE
NRZE
RTOIE
RIE
RLSE
TIE
RAVIE
Register ISR (Sheet 1 of 2)
Bits Name Description
31:5 (Reserved)
4RXPL
Receive Data Polarity:
0 = SIR decoder takes positive pulses as zeros
1 = SIR decoder takes negative pulses as zeros
3TXPL
Transmit Data Polarity:
0 = SIR encoder generates a positive pulse for a data bit of zero
1 = SIR encoder generates a negative pulse for a data bit of zero