External Interrupts
5 external interrupt signals: XINT1, XINT2,
XINT3, XINT4 and XINT5
Each can be mapped to any of GPIO pins via
the X-Bar Input architecture
XINT1, XINT2 and XINT3 also each have a
free-running 16-bit counter that measures
the elapsed time between interrupts
The counter resets to zero each time the
interrupt occurs
Configuring External Interrupts
Input X-Bar selects GPIO pins as sources for XINT1-5
XINT1-5 are sources for Input X-Bar signals 4, 5, 6, 13, and 14
respectively
Configuration Register controls the enable/disable and polarity
Counter Register holds the interrupt counter
Interrupt Pin Selection Configuration Register Counter Register
(Input X-Bar) (XintRegs.register) (XintRegs.register)
XINT1 X-Bar INPUT4 XINT1CR XINT1CTR
XINT2 X-Bar INPUT5 XINT2CR XINT2CTR
XINT3 X-Bar INPUT6 XINT3CR XINT3CTR
XINT4 X-Bar INPUT13 XINT4CR
XINT5 X-Bar INPUT14 XINT5CR
Configuring external interrupts is a two-step process:
Enable interrupt and set polarity
Select XINT1-5 GPIO pins via Input X-Bar