CHAPTER 12 SERIAL INTERFACE 20
(b) Asynchronous serial interface mode register 20 (ASIM20)
ASIM20 is set with a 1-bit or 8-bit memory manipulation instruction.
RESET input sets ASIM20 to 00H.
When 3-wire serial I/O mode is selected, ASIM20 must be set to 00H.
Symbol
ASIM20
<7>
<6>
5
4
3
2
1
0
0
0
Address
FF70H
After reset
00H
R/W
R/W
TXE20
RXE20
PS201
PS200
CL20
SL20
TXE20
Transmit operation control
Receive operation control
Parity bit specification
0
1
Transmit operation stopped
Transmit operation enabled
RXE20
0
1
Receive operation stopped
Receive operation enabled
PS201
PS200
0
0
0
1
No parity
Always add 0 parity at transmission.
Parity check is not performed at reception (No parity error occurs).
Odd parity
Even parity
1
1
0
1
CL20
Transmit data character length specification
Transmit data stop bit length specification
0
1
7 bits
8 bits
SL20
0
1
1 bit
2 bits
Cautions 1. Bits 0 and 1 must be set to 0.
2. Switch operating modes after halting the serial transmit/receive operation.
User’s Manual U15075EJ1V0UM00
238
NEC [ NEC ]
