Serial Interface Channel 2 Operation; Operation Stop Mode - NEC PD78081(A) User Manual

11.4 Serial Interface Channel 2 Operation

Serial interface channel 2 has the following three modes.

• Operation stop mode

• Asynchronous serial interface (UART) mode
• 3-wire serial I/O mode
11.4.1 Operation stop mode
In the operation stop mode, serial transfer is not performed, and therefore power consumption can be reduced.
In the operation stop mode, the P70/SI2/RxD, P71/SO2/TxD and P72/SCK2/ASCK pins can be used as normal
input/output ports.
(1) Register setting
Operation stop mode settings are performed using serial operating mode register 2 (CSIM2) and the
asynchronous serial interface mode register (ASIM).
(a) Serial operating mode register 2 (CSIM2)
CSIM2 is set with a 1-bit or 8-bit memory manipulation instruction.
RESET input sets CSIM2 to 00H.
Symbol
7 6
CSIM2 CSIE2 0
Caution Set 0 to the bits 0 and 3 to 6.
148
CHAPTER 11 SERIAL INTERFACE CHANNEL 2
5 4 3 2
CSIM
0 0 0 CSCK
22
1 0 Address After Reset
0 FF72H
CSIE2 Operation Control in 3-wire Serial I/O Mode
0 Operation stopped
1 Operation enabled
R/W
00H R/W