M16C User Manual.pdf

Programmable I/O PortsMitsubishi microcomputersM16C / 62 GroupSINGLE-CHIP 16-BIT CMOS MICROCOMPUTER(6) I/O functions of built-in peripheral devicesTable 2.15.1 shows relation between ports and I/O functions of built-in peripheral devices.Table 2.15.1. Relation between ports and I/O functions of built-in peripheral devicesP6P71PortP15 to P17P70P72 to P73P74 to P75P76 to P77P80, P81 Timer A I/O pinsP82 to P84I/O pins for serial I/O communicationInternal peripheral device I/O pinsI/O pins for serial I/O communication/Timer A I/O pins/Timer B input pinInput pins for external interruptP86, P87 Sub-clock oscillation circuit I/O pinsP90 to P92Timer B input pinsP93, P94 D-A converter output pinsP95, P96 A-D converter extended input pinsP97P100 to P103P104 to P107Input pins for external interruptI/O pins for serial I/O communication/Timer A I/O pinI/O pins for serial I/O communication/Timer A I/O pins/Three-phase motorcontrol output pinsTimer A I/O pins/Three-phase motor control output pinsTimer A I/O pinsA-D trigger input pinA-D converter input pinsA-D converter input pins / key-input interrupt function input pins(7) Examples of working on non-used pinsTable 2.15.2 contains examples of working on non-used pins. There are shown here for mere examples.In practical use, make suitable changes and perform sufficient evaluation in compliance withyou application.(a) Single-chip modeTable 2.15.2. Examples of working on unused pins in single-chip modePin namePorts P0 to P10 (excluding P85)XOUT (Note 2)NMIAVCCAVSS, VREF, BYTEConnectionAfter setting for input mode, connect every pin to VSS or VCC via aresistor; or after setting for output mode, leave these pins open.(Note 1, Note 3)OpenConnect to VCC via a resistorConnect to VCCConnect to VSSNote 1:Note 2:Note 3:If setting these pins in output mode and opening them, ports are in input mode until switched intooutput mode by use of software after reset. Thus the voltage levels of the pins become unstable,and there can be instances in which the power source current increases while the ports are ininput mode.In view of an instance in which the contents of the direction registers change due to a runawaygenerated by noise or other causes, setting the contents of the direction registers periodically byuse of software increases program reliability.When an external clock is input to the XIN pin.Output "L" if port P70 and P71 are set to output mode.Port P70 and P71 are N channel open drain.447