Enabling External Interrupts in FX2LP

Question: How to enable to external interrupts in FX2LP?

 

Answer:

There are 5 external interrupts in FX2LP. They are INT0, INT1, INT4, INT5 and INT6. INT0 and INT1 are alternate functions of Port A pins PA0 and PA1. The alternate function on these pins is enabled by setting bits 0 and 1 of PORTACFG register. These Interrupts are by default active low and level sensitive. They can be made edge sensitive by setting bits 0 and 2 of SFR TCON. The interrupts are enabled by setting bits EX0 and EX1 (bits 0 and 2 of SFR IE).

INT4 is autovectored FIFO/GPIF Interrupt but it can be configured as External Interrupt 4 on 100- and 128-pin EZ-USB only. This can be done by clearing the INT4VEC bit in the INTSETUP register. It is an edge sensitive and active high interrupt and has a dedicated pin.

INT5 is an edge sensitive and active low interrupt and has a dedicated pin.

INT6 is an alternate function of port E pin PE5. The alternate function can be enabled by setting bit 5 of PORTECFG register.

INT4, INT5 and INT6 are enabled by setting bits 2,3 and 4 of SFR EIE.