M16C62_M Datasheet, PDF (500/615 Pages) Renesas Technology Corp – 16-BIT SINGLE-CHIP MICROCOMPUTER M16C FAMILY / M16C/60 SERIES

Programmable I/O Ports
Mitsubishi microcomputers
M16C / 62A Group
SINGLE-CHIP 16-BIT CMOS MICROCOMPUTER
(b) Memory expansion mode, microprocessor mode
Table 2.16.3. Examples of working on unused pins in memory expansion mode or microprocessor mode
Pin name
Connection
Ports P6 to P10 (excluding P85) After setting for input mode, connect every pin to VSS or VCC via a
resistor; or after setting for output mode, leave these pins open.
(Note 1, Note 2, Note 5)
BHE, ALE, HLDA
Open (Note 3)
XOUT (Note 4), BCLK (Note 6) Open
HOLD, RDY, NMI
Connect via resistor to VCC (pull-up)
AVCC
Connect to VCC
AVSS, VREF
Connect to VSS
Note 1: If setting these pins in output mode and opening them, ports are in input mode until switched into
output 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 in
input mode.
In view of an instance in which the contents of the direction registers change due to a runaway
generated by noise or other causes, setting the contents of the direction registers periodically by
use of software increases program reliability.
Note 2: Make wiring as short as possible (not more than 2 cm from the microcomputer's pins) in working
on non-used pins.
Note 3: When a VSS level is connected to the CNVSS pin, these pins are input ports until the processor
mode is switched by use of software after reset. Thus the voltage levels of the pins destabilize,
and there can be an increase in the power source current while these pins are input ports.
Note 4: When an external clock is input to the XIN pin.
Note 5: Output "L" if port P70 and P71 are set to output mode.
Port P70 and P71 are N channel open drain output.
Note 6: When the BCLK output disable bit (bit 7 at address 000416) is set to “1”, connect to VCC via a
resistor (pull-up).
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