UM10462
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© NXP B.V. 2016. All rights reserved.
User manual
Rev. 5.5 — 21 December 2016
259 of 523
NXP Semiconductors
UM10462
Chapter 12: LPC11U3x/2x/1x USART
The PulseDiv bits in the ICR are used to select the pulse width when the fixed pulse width
mode is used in IrDA mode (IrDAEn = 1 and FixPulseEn = 1). The value of these bits
should be set so that the resulting pulse width is at least 1.63 µs.
shows the
possible pulse widths.
Table 245: IrDA Control Register (ICR - 0x4000 8024) bit description
Bit
Symbol
Value Description
Reset
value
0
IRDAEN
IrDA mode enable
0
0
IrDA mode is disabled.
1
IrDA mode is enabled.
1
IRDAINV
Serial input inverter
0
0
The serial input is not inverted.
1
The serial input is inverted. This has no effect on the
serial output.
2
FIXPULSEEN
IrDA fixed pulse width mode.
0
0
IrDA fixed pulse width mode disabled.
1
IrDA fixed pulse width mode enabled.
5:3
PULSEDIV
Configures the pulse width when FixPulseEn = 1.
0
0x0
3 / (16
baud rate)
0x1
2
T
PCLK
0x2
4
T
PCLK
0x3
8
T
PCLK
0x4
16
T
PCLK
0x5
32
T
PCLK
0x6
64
T
PCLK
0x7
128
T
PCLK
31:6 -
Reserved, user software should not write ones to
reserved bits. The value read from a reserved bit is not
defined.
0
Table 246: IrDA Pulse Width
FixPulseEn
PulseDiv
IrDA Transmitter Pulse width (µs)
0
x
3 / (16
baud rate)
1
0
2
T
PCLK
1
1
4
T
PCLK
1
2
8
T
PCLK
1
3
16
T
PCLK
1
4
32
T
PCLK
1
5
64
T
PCLK
1
6
128
T
PCLK
1
7
256
T
PCLK