UM10503
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© NXP B.V. 2012. All rights reserved.
User manual
Rev. 1.3 — 6 July 2012
985 of 1269
NXP Semiconductors
UM10503
Chapter 38: LPC43xx UART1
38.6 Register description
UART1 contains registers organized as shown in
. The Divisor Latch Access Bit
(DLAB) is contained in LCR[7] and enables access to the Divisor Latches.
Reset value reflects the data stored in used bits only. It does not include the content of
reserved bits.
Table 848: Register overview: UART1 (base address 0x4008 2000)
Name
Access Address
offset
Description
Reset
value
Reference
RBR
RO
0x000
Receiver Buffer Register. Contains the next received
character to be read. (DLAB=0)
NA
THR
WO
0x000
Transmit Holding Register. The next character to be
transmitted is written here. (DLAB=0)
NA
DLL
R/W
0x000
Divisor Latch LSB. Least significant byte of the baud rate
divisor value. The full divisor is used to generate a baud
rate from the fractional rate divider. (DLAB=1)
0x01
DLM
R/W
0x004
Divisor Latch MSB. Most significant byte of the baud rate
divisor value. The full divisor is used to generate a baud
rate from the fractional rate divider.(DLAB=1)
0x00
IER
R/W
0x004
Interrupt Enable Register. Contains individual interrupt
enable bits for the 7 potential UART1 interrupts.
(DLAB=0)
0x00
IIR
RO
0x008
Interrupt ID Register. Identifies which interrupt(s) are
pending.
0x01
FCR
WO
0x008
FIFO Control Register. Controls UART1 FIFO usage and
modes.
0x00
LCR
R/W
0x00C
Line Control Register. Contains controls for frame
formatting and break generation.
0x00
MCR
R/W
0x010
Modem Control Register. Contains controls for flow
control handshaking and loopback mode.
0x00
LSR
RO
0x014
Line Status Register. Contains flags for transmit and
receive status, including line errors.
0x60
MSR
RO
0x018
Modem Status Register. Contains handshake signal
status flags.
0x00
SCR
R/W
0x01C
Scratch Pad Register. 8-bit temporary storage for
software.
0x00
ACR
R/W
0x020
Auto-baud Control Register. Contains controls for the
auto-baud feature.
0x00
FDR
R/W
0x028
Fractional Divider Register. Generates a clock input for
the baud rate divider.
0x10
TER
R/W
0x030
Transmit Enable Register. Turns off UART transmitter for
use with software flow control.
0x80
RS485CTRL
R/W
0x04C
RS-485/EIA-485 Control. Contains controls to configure
various aspects of RS-485/EIA-485 modes.
0x00
RS485ADRMATCH
R/W
0x050
RS-485/EIA-485 address match. Contains the address
match value for RS-485/EIA-485 mode.
0x00
RS485DLY
R/W
0x054
RS-485/EIA-485 direction control delay.
0x00