Renesas 16-bit single-chip microcomputer Manual De Usuario

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Rev.1.02    Jul 01, 2005    page 305 of 314
REJ09B0126-0102
M16C/6N Group (M16C/6NL, M16C/6NN)
22. Usage Precaution
Under development
This document is under development and its contents are subject to change.
22.15 Dedicated Input Pin
When dedicated input pin voltage is larger than VCC pin voltage, latch up occurs.
When different power supplied to the system, and input voltage of unused dedicated input pin is larger than
voltage of VCC pin, connect dedicated input pin to VCC via resistor (approximately 1k
Ω).
Figure 22.8 shows the circuit connection.
This note is also applicable when VINPUT exceeds VCC during power-up.
The resistor is not necessary when VCC pin voltage is same or larger than dedicated input pin voltage.
Figure 22.8  Circuit Connection
VCC
Dedicated
input pin
(e.g. NMI)
Different power supply
M16C/6NL, M16C/6NN