Renesas R8C series User Manual

R8C/1A Group, R8C/1B Group 20. Usage Notes
Rev.1.30 Dec 08, 2006 Page 308 of 315
REJ09B0252-0130
20.8 Notes on Noise
20.8.1 Inserting a Bypass Capacitor between VCC and VSS Pins as a Countermeasure
against Noise and Latch-Up
Connect a bypass capacitor (at least 0.1 µF) using the shortest and thickest wire possible.
20.8.2 Countermeasures against Noise Error of Port Control Registers
During rigorous noise testing or the like, external noise (mainly power supply system noise) can exceed the
capacity of the MCU’s internal noise control circuitry. In such cases the contents of the port related registers
may be changed.
As a firmware countermeasure, it is recommended that the port registers, port direction registers, and pull-up
control registers will be reset periodically. However, examine the control processing fully before introducing
the reset routine as conflicts may be created between the reset routine and interrupt routines.

Renesas R8C series Specifications

General

Brand	Renesas
Model	R8C series
Category	Computer Hardware
Language	English