M16C User Manual.pdf

UARTMitsubishi microcomputersM16C / 62 GroupSINGLE-CHIP 16-BIT CMOS MICROCOMPUTER2.5.3 Operation of Serial I/O (reception in UART mode)In receiving data in UART mode, choose functions from those listed in Table 2.5.5. Operations of thecircled items are described below. Figure 2.5.11 shows the operation timing, and Figures 2.5.12 and2.5.13 show the set-up procedures.Table 2.5.5. Choosed functionsItemSet-upItemSet-upTransfer clocksource(Note 2)RTS functionCTS / RTSseparation function(Note 1)Sleep mode(Note 2)OOOOInternal clock (f1 / f8 / f32)External clock (CLKi pin)RTS function enabledRTS function disabledPin shared by CTS and RTSCTS and RTS separateSleep mode offSleep mode selectedData logic selectfunction(Note 3)TXD, RXD I/Opolarity reverse bit(Note 3)Bus collisiondetection function(Note 3)OOONo reverseReverseNo reverseReverseNot selectedSelected_______ ________Note 1: UART0 only. (UART1 CTS/RTS function cannot be used when this function is selected.)Note 2: UART0, UART1 only.Note 3: UART2 only.Operation(1) Setting the receive enable bit to “1” readies data-receivable status. At this time, output from________the RTSi pin goes to “L” level to inform the transmission side that the receivable status isready.(2) When the first bit (the start bit) of reception data is received from the RxDi pin, output from the_______RTS goes to “H” level. Then, data is received, bit by bit, in sequence: LSB, ····, MSB, and stopbit(s).(3) When the stop bit(s) is (are) received, the content of the UARTi receive register is transmittedto the UARTi receive buffer register.At this time, the receive complete flag goes to “1” to indicate that the reception is completed, the_______UARTi receive interrupt request bit goes to “1”, and output from the RTS pin goes to “L” level.(4) The receive complete flag goes to “0” when the lower-order byte of the UARTi buffer registeris read.362