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CHAPTER 15 SERIAL INTERFACE CSI10
User’s Manual U19780EJ2V0UD
403
(1) Transmit buffer register 10 (SOTB10)
This register sets the transmit data.
Transmission/reception is started by writing data to SOTB10 when bit 7 (CSIE10) and bit 6 (TRMD10) of serial
operation mode register 10 (CSIM10) is 1.
The data written to SOTB10 is converted from parallel data into serial data by serial I/O shift register 10, and
output to the serial output pin (SO10).
SOTB10 can be written or read by an 8-bit memory manipulation instruction.
Reset signal generation clears this register to 00H.
Cautions 1. Do not access SOTB10 when CSOT10 = 1 (during serial communication).
2. In the case of 78K0/KC2-A, in the slave mode, transmission/reception is started when data
is written to SOTB11 with a low level input to the SSI10 pin. For details on the
transmission/reception operation, refer to 15.4.2 (2) Communication operation.
(2) Serial I/O shift register 10 (SIO10)
This is an 8-bit register that converts data from parallel data into serial data and vice versa.
This register can be read by an 8-bit memory manipulation instruction.
Reception is started by reading data from SIO10 if bit 6 (TRMD10) of serial operation mode register 10 (CSIM10)
is 0.
During reception, the data is read from the serial input pin (SI10) to SIO10.
Reset signal generation clears this register to 00H.
Cautions 1. Do not access SIO10 when CSOT10 = 1 (during serial communication).
2. In the case of 78K0/KC2-A, in the slave mode, reception is started when data read from
SIO10 with a low level input to the SSI10 pin. For details on the reception operation, refer to
15.4.2 (2) Communication operation.