237
CHAPTER 14 SERIAL INTERFACE (SIO3)
Preliminary User’s Manual U16035EJ1V0UM
14.2 Configuration of Serial Interface
The serial interface (SIO3n) consists of the following hardware.
Table 14-1. Configuration of Serial Interface (SIO3n)
Item
Configuration
Register
Serial I/O shift register 3n (SIO3n)
Control register
Serial operation mode register 3n (CSIM3n)
Remark
n = 0, 1
(1) Serial I/O shift register 3n (SIO3n)
This is an 8-bit register that performs parallel-serial conversion and serial transmit/receive (shift operations)
synchronized with the serial clock.
SIO3n is set by an 8-bit memory manipulation instruction.
When 1 is set to bit 7 (CSIE3n) of the serial operation mode register 3n (CSIM3n), a serial operation can be started
by writing data to or reading data from SIO3n.
When transmitting, data written to SIO3n is output to the serial output (SO3n).
When receiving, data is read from the serial input (SI3n) and written to SIO3n.
RESET input makes SIO3n undefined.
Caution
Do not access SIO3n during a transfer operation unless the access is triggered by a transfer
start (read operation is disabled when MODEn = 0 and write operation is disabled when MODEn
= 1).
Remark
n = 0, 1