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UM10503
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© NXP B.V. 2012. All rights reserved.
User manual
Rev. 1.3 — 6 July 2012
954 of 1269
NXP Semiconductors
UM10503
Chapter 37: LPC43xx USART0_2_3
37.6.4 USART Interrupt Enable Register
The IER is used to enable the four USART interrupt sources.
Table 824. USART Divisor Latch LSB Register when DLAB = 1 (DLL - addresses 0x4008 1000
(USART0), 0x400C 1000 (USART2), 0x400C 2000 (USART3)) bit description
Bit
Symbol
Description
Reset value
7:0
DLLSB
Divisor latch LSB.
The USART Divisor Latch LSB Register, along with the DLM
register, determines the baud rate of the USART.
0x01
31:8 -
Reserved
-
Table 825. USART Divisor Latch MSB Register when DLAB = 1 (DLM - addresses
0x4008 1004 (USART0), 0x400C 1004 (USART2), 0x400C 2004 (USART3)) bit
description
Bit
Symbol
Description
Reset value
7:0
DLMSB
Divisor latch MSB.
The USART Divisor Latch MSB Register, along with the DLL
register, determines the baud rate of the USART.
0x00
31:8 -
Reserved
-
Table 826. USART Interrupt Enable Register when DLAB = 0 (IER - addresses 0x4008 1004
(USART0), 0x400C 1004 (USART2), 0x400C 2004 (USART3)) bit description
Bit
Symbol
Value
Description
Reset
value
0
RBRIE
RBR Interrupt Enable.
Enables the Receive Data Available interrupt for USART. It
also controls the Character Receive Time-out interrupt.
0
0
Disable the RDA interrupt.
1
Enable the RDA interrupt.
1
THREIE
THRE Interrupt Enable.
Enables the THRE interrupt for USART. The status of this
interrupt can be read from LSR[5].
0
0
Disable the THRE interrupt.
1
Enable the THRE interrupt.
2
RXIE
RX Line Interrupt Enable.
Enables the USART RX line status interrupts. The status of
this interrupt can be read from LSR[4:1].
0
0
Disable the RX line status interrupts.
1
Enable the RX line status interrupts.
3
-
-
Reserved
-
6:4
-
Reserved, user software should not write ones to reserved
bits. The value read from a reserved bit is not defined.
NA
7
-
-
Reserved
0
8
ABEOINTEN
Enables the end of auto-baud interrupt.
0
0
Disable end of auto-baud Interrupt.
1
Enable end of auto-baud Interrupt.