MS51
Dec. 17, 2019
Page
254
of 316
Rev 1.01
M
S51
SE
RIES
TE
CHNICA
L REF
ERE
N
CE MA
NU
A
L
AUXR1
– Auxiliary Register 1
Regiser
Address
Reset Value
AUXR1
A2H, all pages
POR 0000_0000b,
Software 1U00_0000b
nRESET pin U100_0000b
Others UUU0_0000b
7
6
5
4
3
2
1
0
SWRF
RSTPINF
HardF
SLOW
GF2
UART0PX
0
DPS
R/W
R/W
R/W
R/W
R/W
R/W
R
R/W
Bit
Name
Description
2
UART0PX
Serial port 0 pin exchange
0 = Assign RXD to P0.7 and TXD to P0.6 by default.
1 = Exchange RXD to P0.6 and TXD to P0.7.
Note that TXD and RXD will exchange immediately once setting or clearing this bit. User should
take care of not exchanging pins during transmission or receiving. Or it may cause unpredictable
situation and no warning alarms.