CHAPTER 11 SERIAL INTERFACE 20
User’s Manual U15331EJ4V1UD
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(2) Asynchronous serial interface mode register 20 (ASIM20)
ASIM20 is used to make the settings related to asynchronous serial interface mode.
ASIM20 is set with a 1-bit or 8-bit memory manipulation instruction.
RESET input sets ASIM20 to 00H.
Figure 11-4. Format of Asynchronous Serial Interface Mode Register 20
TXE20
0
1
Transmit operation control
TXE20 RXE20 PS201 PS200 CL20
SL20
0
0
ASIM20
Symbol
Address
After reset
R/W
FF70H
00H
R/W
<7>
<6>
5
4
3
2
1
0
Transmit operation stopped
Transmit operation enabled
RXE20
0
1
Receive operation control
Receive operation stopped
Receive operation enabled
PS201
0
0
1
1
Parity bit specification
PS200
0
1
0
1
No parity
Always add 0 parity at transmission.
Parity check is not performed at reception (no parity error is generated).
Odd parity
Even parity
CL20
0
1
Transmit data character length specification
7 bits
8 bits
SL20
0
1
Transmit data stop bit length
1 bit
2 bits
Cautions 1. Bits 0 and 1 must be set to 0.
2. If 3-wire serial I/O mode is selected, ASIM20 must be set to 00H.
3. Switch operation modes after halting the serial transmission/reception operation.