NEC PD78F9488 - Manual (Page 191)

CHAPTER 11 SERIAL INTERFACE 20
User’s Manual U15331EJ4V1UD
191
(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.