How can I create a delay in my XC8 program?

If an accurate delay is required, or if there are other tasks that can be performed during the delay, then using a timer to generate an interrupt is the best way to proceed.

If this is not an option, then you can use the MPLAB® XC8 compiler’s in-built delay functions: _delay, __delay_ms or __delay_us.

  • These all expand into in-line instructions or a (nested) loop of instructions.
  • The delay amount must be a constant (cannot be a variable).
  • The Delay value should be less than 179,200 for PIC18 devices and 50,659,000 for other devices
  • The delay value is the number of instruction cycles that will be executed by the delay.

To use these functions, you must tell the compiler what your oscillator frequency is by adding a line like the following near the top of your C file:

Please refer to the compiler manual for more details about delay routines.

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