How to use a variable delay in Microchip PIC microcontroller (MPLAB X), without using floating point arithmetic?

Question

I'm using a PIC10F220.

For some reason, this delay works perfectly fine:

__delay_ms(10);

But, when I try to run a delay with a variable, it gets an error. This error indicates that it is trying to include libraries to do floating point arithmetic.

char delayConst = 10;
__delay_ms(delayConst);

Error:

Non line specific message::: error: (1359) no space for ___ftmul parameters

This also happens for the unsigned char, int, unsigned int, and unsigned short int types using delayConst.

It continues to occur even if I block out large sections of code.

Although I used the name "delayConst", actually, I need this delay to vary throughout the code (be added and subtracted to). So that's why this is a problem.

Answer 1

__delay_ms and __delay_us are macro's. They are expanded at compile time by the preprocessor and thus only accept constants as parameter.

If you need a simple variable delay just create a function that executes a fixed delay in a loop:

//Delay n times 10 ms...
void MyDelay(uint8_t n)
{
    for (; n > 0; n--)
    {
        __delay_ms(10);
    }
}