Mitsubishi Electric M32R Series User Manual page 848

Appendix 3
Appendix 3.1.5 Processing Input/Output Ports
For input/output ports, take the appropriate measures in both hardware and software following the
procedure described below.
Hardware measures
_ Insert resistors of 100 Ω (or more) in series to input/output ports.
Software measures
• For input ports, read out data in a program two or more times to verify that levels match.
• For output ports, rewrite the data register at certain intervals, because there is a possibility of
the output data being inverted by noise.
• Rewrite the direction register at certain intervals.
Figure 3.1.8 Processing Input/Output Ports
Data bus
Direction register
Data register
Appendix 3-8
PRECAUTIONS ABOUT NOISE
Appendix 3.1 Precautions about Noise
Noise
Noise
Input/output port
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