UM10429
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© NXP B.V. 2010. All rights reserved.
User manual
Rev. 1 — 20 October 2010
77 of 258
NXP Semiconductors
UM10429
Chapter 10: LPC1102 Universal Asynchronous Transmitter (UART)
10.5.8 UART Line Status Register
The U0LSR is a Read Only register that provides status information on the UART TX and
RX blocks.
3
PE
Parity Enable
0
0
Disable parity generation and checking.
1
Enable parity generation and checking.
5:4
PS
Parity Select
0
0x0
Odd parity. Number of 1s in the transmitted character and the
attached parity bit will be odd.
0x1
Even Parity. Number of 1s in the transmitted character and the
attached parity bit will be even.
0x2
Forced 1 stick parity.
0x3
Forced 0 stick parity.
6
BC
Break Control
0
0
Disable break transmission.
1
Enable break transmission. Output pin UART TXD is forced to logic
0 when U0LCR[6] is active high.
7
DLAB
Divisor Latch Access Bit (DLAB)
0
0
Disable access to Divisor Latches.
1
Enable access to Divisor Latches.
31:
8
-
-
Reserved
-
Table 80.
UART Line Control Register (U0LCR - address 0x4000 800C) bit description
Bit
Symbol Value Description
Reset
Value
Table 81.
UART Line Status Register (U0LSR - address 0x4000 8014, Read Only) bit
description
Bit Symbol
Value Description
Reset
Value
0
RDR
Receiver Data Ready:U0LSR[0] is set when the U0RBR holds
an unread character and is cleared when the UART RBR FIFO
is empty.
0
0
U0RBR is empty.
1
U0RBR contains valid data.
1
OE
Overrun Error
The overrun error condition is set as soon as it occurs. A
U0LSR read clears U0LSR[1]. U0LSR[1] is set when UART
RSR has a new character assembled and the UART RBR FIFO
is full. In this case, the UART RBR FIFO will not be overwritten
and the character in the UART RSR will be lost.
0
0
Overrun error status is inactive.
1
Overrun error status is active.