5.22 __restore_interrupt Intrinsic Function

The IAR __restore_interrupt intrinsic function restores the interrupt flag to a state obtained using the __save_interrupt intrinsic function.

Suggested Replacement

There is no equivalent MPLAB XC8 built-in function, but the SREG registers can be updated with plain C code.

Use code that performs a bitwise OR of the SREG register and a saved value obtained from that same register before the interrupt flags were potentially changed.

Caveats

None

Examples

Consider migrating IAR code such as:

unsigned char saved;

void foo(void) {
    saved = __save_interrupt();
    __disable_interrupt();
    /* Critical section goes here */
    __restore_interrupt(saved);
}

to MPLAB XC8 code similar to:

volatile unsigned char saved;

void foo(void) {
    saved = (SREG & 0x80);
    di();
    /* Critical section goes here */
    SREG |= saved;
}