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How to see the modification after rewriting value of a variable?

Latest Updated:05/18/2015


I am using the CC-RL compiler for RL78 devices. I have attempted to rewrite the value of a variable from an interrupt function but the variable does not reflect the change of value I’m trying to make.


Add the volatile qualifier to the declaration of any external variable to which a normal function or interrupt function refers.


int data;
void func(int x)

data = x; /* <- After a value is assigned to the variable “data”, even though    the interrupt function appears to write a new value to the variable, its value may not reflect this change. This is because the compiler uses the value of the variable “data” that has been stored in a register in advance. */
	if(data == 0)
volatile int data;

To prevent this problem, add the above declaration.

Suitable Products
e² studio
CS+ (formerly CubeSuite+)
C Compiler Package for RL78 Family