UM10208_2
© NXP B.V. 2007. All rights reserved.
User manual
Rev. 02 — 1 June 2007
156 of 362
NXP Semiconductors
UM10208
Chapter 14: LPC2800 UART
3.5 Interrupt Enable Register (IER - 0x8010 1004 when DLAB=0)
When bit 0 of the NHP Mode Register (described in
) is 0, the IER
controls which events are enabled to assert the UART’s interrupt request.
Table 169. Divisor Latch LSB Register (DLL - 0x8010 1000 when DLAB=1)
Bit
Symbol Description
Reset
Value
7:0
DLL
The Divisor Latch LSB Register, along with the DLM register, determines
the baud rate of the UART.
0x01
31:8
-
Reserved, user software should not write ones to reserved bits. The value
read from a reserved bit is not defined.
-
Table 170. Divisor Latch MSB Register (DLM - 0x8010 1004 when DLAB=1)
Bit
Symbol Description
Reset
Value
7:0
DLM
The Divisor Latch MSB Register, along with the DLL register, determines
the baud rate of the UART.
0
31:8
-
Reserved, user software should not write ones to reserved bits. The value
read from a reserved bit is not defined.
-
Table 171. Interrupt Enable Register (IER - 0x8010 1004 when DLAB=0)
Bit
Name
Description
Reset
Value
0
RDAIntEn
A 1 in this bit enables the Receive Data Available interrupt. It also
controls the Character Receive Time-out interrupt.
0
1
THREIntEn A 1 in this bit enables the THRE interrupt. THRE can be read as
LSR[5].
0
2
RLSIntEn
A 1 in this bit enables RX line status interrupts. The status of this
interrupt can be read from LSR[4:1].
0
3
MSIntEn
If Auto CTS operation is disabled (MCR[7]=0), a 1 in this bit enables
interrupt transitions on transitions of the CTS pin. If Auto CTS
operation is enabled (MCR[7]=1), both this bit and CTSIntEn (bit 7)
must be 1 to enable such interrupts.
6:4
-
Reserved, user software should not write ones to reserved bits. The
value read from a reserved bit is not defined.
-
7
CTSIntEn
If Auto CTS operation is enabled (MCR[7]=1), both this bit and
MSIntEn (bit 3) must be 1 to enable interrupts on transitions of the
CTS pin.
0
8
ABEOIntEn A 1 in this bit enables an interrupt when an auto-baud operation
completes.
0
9
ABTOIntEn A 1 in this bit enables an interrupt when an auto-baud operation
times out.
0
31:10
-
Reserved, user software should not write ones to reserved bits. The
value read from a reserved bit is not defined.
-