
DR
AFT
DR
AFT
DRAFT
DR
D
RAFT
DRAFT
DRA
FT DRAF
D
RAFT DRAFT DRAFT DRAFT DRAFT D
DRAFT
D
RAFT DRA
FT DRAFT DRAFT DRAFT DRA
UM10360_0
© NXP B.V. 2009. All rights reserved.
User manual
Rev. 00.06 — 5 June 2009
280 of 808
NXP Semiconductors
UM10360
Chapter 14: LPC17xx UART0/2/3
4.9 UARTn Scratch Pad Register (U0SCR - 0x4000 C01C, U2SCR -
0x4009 801C U3SCR - 0x4009 C01C)
The UnSCR has no effect on the UARTn operation. This register can be written and/or
read at user’s discretion. There is no provision in the interrupt interface that would indicate
to the host that a read or write of the UnSCR has occurred.
4.10 UARTn Auto-baud Control Register (U0ACR - 0x4000 C020, U2ACR -
0x4009 8020, U3ACR - 0x4009 C020)
The UARTn Auto-baud Control Register (UnACR) controls the process of measuring the
incoming clock/data rate for the baud rate generation and can be read and written at
user’s discretion.
6
Transmitter
Empty
(TEMT)
TEMT is set when both UnTHR and UnTSR are empty; TEMT
is cleared when either the UnTSR or the UnTHR contain valid
data.
1
0
UnTHR and/or the UnTSR contains valid data.
1
UnTHR and the UnTSR are empty.
7
Error in RX
FIFO
(RXFE)
UnLSR[7] is set when a character with a Rx error such as
framing error, parity error or break interrupt, is loaded into the
UnRBR. This bit is cleared when the UnLSR register is read
and there are no subsequent errors in the UARTn FIFO.
0
0
UnRBR contains no UARTn RX errors or UnFCR[0]=0.
1
UARTn RBR contains at least one UARTn RX error.
Table 258: UARTn Line Status Register (U0LSR - address 0x4000 C014,
U2LSR - 0x4009 8014, U3LSR - 0x4009 C014, Read Only) bit description
Bit Symbol
Value Description
Reset
Value
Table 259: UARTn Scratch Pad Register (U0SCR - address 0x4000 C01C,
U2SCR - 0x4009 801C, U3SCR - 0x4009 C01C) bit description
Bit Symbol Description
Reset
Value
7:0 Pad
A readable, writable byte.
0x00
Table 260: UARTn Auto-baud Control Register (U0ACR - address 0x4000 C020, U2ACR -
0x4009 8020, U3ACR - 0x4009 C020) bit description
Bit
Symbol
Value Description
Reset value
0
Start
This bit is automatically cleared after auto-baud
completion.
0
0
Auto-baud stop (auto-baud is not running).
1
Auto-baud start (auto-baud is running). Auto-baud run
bit. This bit is automatically cleared after auto-baud
completion.
1
Mode
Auto-baud mode select bit.
0
0
Mode 0.
1
Mode 1.