Serial Interface 20 Operation Mode Settings - NEC PD789488 User Manual

(1) Operation stop mode
ASIM20 CSIM20
TXE20 RXE20 CSIE20 DIR20
0 0 0 ×
(2) 3-wire serial I/O mode
ASIM20 CSIM20
TXE20 RXE20 CSIE20 DIR20
0 0 1 0
1 1
(3) Asynchronous serial interface mode
ASIM20 CSIM20
TXE20 RXE20 CSIE20 DIR20
1 0 0 0
0 1 0 0
1 1 0 0
Notes 1. These pins can be used for port functions.
2. When only transmission is used, this pin can be used as P22 (CMOS I/O).
×: don't care
Remark
192
CHAPTER 11 SERIAL INTERFACE 20
Table 11-2. Serial Interface 20 Operation Mode Settings
PM22 P22 PM21
CSCK20
Note 1 Note 1 Note 1
× × × × ×
Other than above
PM22 P22 PM21
CSCK20
Note 2 Note 2
0 1 × 0
1
0
1
Other than above
PM22 P22 PM21
CSCK20
Note 1 Note 1
0 × × 0
Note 1
0 1 × × ×
×
0 1 0
Other than above
User's Manual U15331EJ4V1UD
P21 PM20 P20 First Shift
Bit Clock
Note 1 Note 1 Note 1
× × − −
Setting prohibited
P21 PM20 P20 First Shift
Bit Clock
1 1 × MSB
External
clock
0 1
Internal
clock
×
1 LSB
External
clock
0 1
Internal
clock
Setting prohibited
P21 PM20 P20 First Shift
Bit Clock
1 1 × LSB
External
clock
Note 1 Note 1
× ×
Internal
clock
Note 1
1 ×
External
clock
Note 1 Note 1
× ×
Internal
clock
×
1 1
External
clock
Note 1 Note 1
× ×
Internal
clock
Setting prohibited
P22/SI20/ P21/SO20/ P20/SCK20/
RxD20 Pin TxD20 Pin ASCK20 Pin
Function Function Function
P22 P21 P20
P22/SI20/ P21/SO20/ P20/SCK20/
RxD20 Pin TxD20 Pin ASCK20 Pin
Function Function Function
Note 2
SI20 SO20 SCK20
input
(CMOS output)
SCK20
output
SCK20
input
SCK20
output
P22/SI20/ P21/SO20/ P20/SCK20/
RxD20 Pin TxD20 Pin ASCK20 Pin
Function Function Function
P22 TxD20 ASCK20
input
(CMOS output)
P20
RxD20 P21 ASCK20
input
P20
TxD20 ASCK20
input
(CMOS output)
P20