4.34.1 enable_external_int
enable_external_int(mask)
This macro gives access to the GIMSK
register (or EIMSK
register if using an AVR Mega device or GICR
register for others). Although this macro is essentially the same as assigning to the register, it does adapt slightly to the type of device being used. This macro is unavailable if none of the registers listed above are defined.