M16C User Manual.pdf

SI/O3, 4Mitsubishi microcomputersM16C / 62 GroupSINGLE-CHIP 16-BIT CMOS MICROCOMPUTER2.6.2 Operation of SI/O3,4In transmitting data in this mode, choose functions from those listed in Table 2.6.1. Operations of thecircled items are described below. Figure 2.6.3 shows the operation timing, and Figures 2.6.4 and 2.6.5show the set-up procedures.Table 2.6.1. Choosed functionsItemSet-upItemSet-upOperationNoteTransfer clocksourceTransfer clockOOInternal clock (f1 / f8 / f32)External clock (CLKi pin)LSB firstMSB firstSOUTi initial valueset functionNot used(1) Transfer begins upon writing the SI/Oi transmit data.The transmit data is sent out from the SOUTi pin synchronously with falling edges of thetransfer clock.(2) When SOUT finishes sending one byte of data, the interrupt request bit is set to 1.(3) After the transfer is completed, SOUT holds the last data for a 1/2 transfer clock period beforegoing to a high-impedance state.• Do not write data to the SI/Oi transmit/receive register (i = 3, 4; addresses 036016, 036416)during a transfer.• Data can only be written to the SI/Oi transmit/receive register when the device is idle neithersending nor receiving data.OUsedExample of wiringMicrocomputerCLKiSOUTiReceiver side ICCLKSINExample of operationInternal clock(1) Transmission enabled1.5 TCLK (Max)(2) Transmissionis complete(3) HighimpedanceSI/Oi transmit/receiveregister write signalTCLKSI/Oi outputSOUTiCLKiD0 D1 D2 D3 D4 D5 D6D7Hi-ZSI/Oi inputSINiSI/Oi interruptrequest bit(i = 3, 4)"1""0"Cleared to “0” when interrupt request is accepted, or cleared by softwareTCLK = 2(n + 1) / fifi: frequency of BRGi count source (f1, f8, f32)n: value set to SiBRGFigure 2.6.3. Operation timing of transmission in SI/O3, 4 mode380