CHAPTER 15 SERIAL INTERFACES CSI10 AND CSI11User’s Manual U16899EJ2V0UD33615.4.2 3-wire serial I/O modeThe 3-wire serial I/O mode is used for connecting peripheral ICs and display controllers with a clocked serialinterface.In this mode, communication is executed by using three lines: the serial clock (SCK1n), serial output (SO1n), andserial input (SI1n) lines.(1) Registers used• Serial operation mode register 1n (CSIM1n)• Serial clock selection register 1n (CSIC1n)• Port mode register 0 (PM0) or port mode register 1 (PM1)• Port register 0 (P0) or port register 1 (P1)The basic procedure of setting an operation in the 3-wire serial I/O mode is as follows.<1> Set the CSIC1n register (see Figures 15-5 and 15-6).<2> Set bits 0 and 4 to 6 (CSOT1n, DIR1n, SSE11 (serial interface CSI11 only), and TRMD1n) of the CSIM1nregister (see Figures 15-3 and 15-4).<3> Set bit 7 (CSIE1n) of the CSIM1n register to 1. → Transmission/reception is enabled.<4> Write data to transmit buffer register 1n (SOTB1n). → Data transmission/reception is started.Read data from serial I/O shift register 1n (SIO1n). → Data reception is started.Caution Take relationship with the other party of communication when setting the port mode registerand port register.Remark n = 0:μPD78F0132Hn = 0, 1:μPD78F0133H, 78F0134H, 78F0136H, 78F0138H, 78F0138HD
