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CHAPTER 11 SERIAL INTERFACES SIO30 TO SIO32
User’s Manual U15104EJ2V0UD
(3) Starting transfer
Serial transfer is started by writing (or reading) the transfer data to serial I/O shift register 3n (SIO3n) when
the following conditions are satisfied.
•
Operation control bit of SIO3n (bit 7 (CSIE3n) of serial operation mode register 3n (CSIM3n)) = 1
•
If the internal serial clock is stopped or SCK3n is high level after transfer of 8-bit serial data
•
Transmit/receive mode
Transfer is started if SIO3n is written when bit 7 (CSIE3n) of CSIM3n = 1, and bit 2 (MODE3n) = 0
•
Receive mode
Transfer is started if SIO3n is read when bit 7 (CSIE3n) of CSIM3n = 1, and bit 2 (MODE3n) = 1
Caution
Serial transfer is not started even if 1 is written to CSIE3n after data is written to SIO3n.
On completion of transfer of the 8-bit data, serial transfer is automatically stopped, and an interrupt request
flag (CSIIF3n) is set.