Enum pl_int_num contains the list of constants that refer to available interrupt lines. Interrupt lines are mapped to GPIO lines (this mapping can't be altered).
Enum pl_int_num includes the following constants:
|0- PL_INT_NUM_0:||Interrupt line 0 (mapped to I/O line 0, which serves as the CTS input of the serial port).|
|1- PL_INT_NUM_1:||Interrupt line 1 (mapped to I/O line 1, which serves as the DSR input of the serial port).|
|2- PL_INT_NULL:||This is a NULL interrupt line that does not physically exist.|