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CHAPTER 16 SERIAL INTERFACE UART0
User’s Manual U15798EJ2V0UD
16.4 Serial Interface UART0 Operations
This section explains the two modes of serial interface UART0.
16.4.1 Operation stop mode
Because serial transfer is not performed during this mode, the power consumption can be reduced.
In addition, pins can be used as normal ports.
(1) Register settings
Operation stop mode is set by asynchronous serial interface mode register 0 (ASIM0).
ASIM0 is set by a 1-bit or 8-bit memory manipulation instruction.
RESET input sets the value of this register to 00H.
Address: FFA0H After reset: 00H R/W
Symbol
7
6
5
4
3
2
1
0
ASIM0
TXE0
RXE0
PS01
PS00
CL0
SL0
ISRM0
0
TXE0
RXE0
Operation mode
RxD0/P26 pin function
TxD0/P27 pin function
0
0
Operation stop
Port function (P26)
Port function (P27)
0
1
UART mode
Serial function (RxD0)
(receive only)
1
0
UART mode
Port function (P26)
Serial function (TxD0)
(transmit only)
1
1
UART mode
Serial function (RxD0)
(transmit and receive)
Caution Before rewriting ASIM0 with a value other than the same value, temporarily stop the operation.