NEC PD78055 Benutzerhandbuch

Serial interface channel 2 has the following three modes.

• Operation stop mode

• Asynchronous serial interface (UART) mode

• 3-wire serial I/O 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.

Operation stop mode settings are performed using serial operating mode register 2 (CSIM2) and the

asynchronous serial interface mode register (ASIM).

CSIM2 is set with a 1-bit or 8-bit memory manipulation instruction.

RESET input sets CSIM2 to 00H.

CSIM

22

6

5

4

3

2

1

0

<7>

Symbol

CSIM2 CSIE2

0

0

0

0

CSCK

0

FF72H              00H           R/W

Address     After Reset     R/W

CSIE2

0

1

Operation Control in 3-wire Serial I/O Mode

Operation stopped

Operation enabled