Interrupt port cause register 0
| PORT_INT | Each IO port has an associated bit field in this register. The bit field reflects the IO port’s interrupt line (bit field i reflects ‘gpio_interrupts[i]’ for IO port i). The register is used when the system uses a combined interrupt line ‘gpio_interrupt’. The software ISR reads the register to determine which IO port(s) is responsible for the combined interrupt line. Once, the IO port(s) is determined, the IO port’s GPIO_PRT_INTR register is read to determine the IO pin(s) in the IO port that caused the interrupt. ‘0’: Port has no pending interrupt ‘1’: Port has pending interrupt |