UM10462
All information provided in this document is subject to legal disclaimers.
© NXP B.V. 2016. All rights reserved.
User manual
Rev. 5.5 — 21 December 2016
267 of 523
NXP Semiconductors
UM10462
Chapter 12: LPC11U3x/2x/1x USART
12.5.20 USART RS-485 Address Match register
The RS485ADRMATCH register contains the address match value for RS-485/EIA-485
mode.
12.5.21 USART RS-485 Delay value register
The user may program the 8-bit RS485DLY register with a delay between the last stop bit
leaving the TXFIFO and the de-assertion of RTS (or DTR). This delay time is in periods of
the baud clock. Any delay time from 0 to 255 bit times may be programmed.
1
RXDIS
Receiver enable.
0
0
The receiver is enabled.
1
The receiver is disabled.
2
AADEN
AAD enable.
0
0
Auto Address Detect (AAD) is disabled.
1
Auto Address Detect (AAD) is enabled.
3
SEL
Select direction control pin
0
0
If direction control is enabled (bit DCTRL = 1), pin
RTS is used for direction control.
1
If direction control is enabled (bit DCTRL = 1), pin
DTR is used for direction control.
4
DCTRL
Auto direction control enable.
0
0
Disable Auto Direction Control.
1
Enable Auto Direction Control.
5
OINV
Polarity control. This bit reverses the polarity of
the direction control signal on the RTS (or DTR)
pin.
0
0
The direction control pin will be driven to logic 0
when the transmitter has data to be sent. It will be
driven to logic 1 after the last bit of data has been
transmitted.
1
The direction control pin will be driven to logic 1
when the transmitter has data to be sent. It will be
driven to logic 0 after the last bit of data has been
transmitted.
31:6 -
-
Reserved, user software should not write ones to
reserved bits. The value read from a reserved bit
is not defined.
NA
Table 253. USART RS485 Control register (RS485CTRL - address 0x4000 804C) bit
description
…continued
Bit
Symbol
Value
Description
Reset
value
Table 254. USART RS-485 Address Match register (RS485ADRMATCH - address
0x4000 8050) bit description
Bit
Symbol
Description
Reset value
7:0
ADRMATCH
Contains the address match value.
0x00
31:8
-
Reserved
-