Input Capture; External Interrupts - Digilent chipKIT MX3 Reference Manual

chipKIT™ MX3 Board Reference Manual
Refer to the PIC32 Family Reference Manual, Section 16, Output Compare for detailed information on the use of
the output compares units.
When using the MPIDE software, these are accessed using the analogWrite() function. The digital pin number, or
preferably, the symbols PIN_OC1 through PIN_OC5 are used to specify the pin. The MPIDE software currently only
supports using the output compare units to generate PWM outputs. It uses Timer2 to control the output
compares.
The following gives Pmod connector position, chipKIT pin number, and microcontroller I/O port and bit number for
the output compare unit's output pins:

OC1 – JC-09, digital pin 23, RD0

OC2 – JC-10, digital pin 24, RD1

OC3 – JD-02, digital pin 25, RD2

OC4 – JD-08, digital pin 29, RD3

OC5 – JB-09, digital pin 14, RD4

13 Input Capture

The PIC32 microcontroller provides five input capture units. An input capture unit works in conjunction with a
timer and monitors the state of an associated pin. When the pin changes state, the current value of the timer is
captured. The input capture units can be used with either Timer2 or Timer3.
The input capture unit can be programmed to be sensitive to either a rising edge, a falling edge, or both edges on
the input pin. An interrupt can also be signaled when an input capture is triggered. Each input capture has a four
level deep FIFO that can buffer up to four capture events.
For detailed information on the operation and use of the input capture units, refer to the PIC32 Family Reference
Manual, Section 15, Input Capture.
The following gives the Pmod connector position, chipKIT pin number, and microcontroller port and bit number for
the input capture units input pins:

IC1 – JE-07, digital pin 32, RD08

IC2 – JB-01, digital pin 8, RD09

IC3 – JD-03, digital pin 26, RD10

IC4 – JD-09, digital pin 30, RD11

IC5 – JB-09, digital pin 14, RD04
Use of the input capture units is not currently supported in the MPIDE software. This will be added in a future
version.

14 External Interrupts

The PIC32 microcontroller provides five external interrupt inputs. An external interrupt input can be used to
generate an interrupt to the microprocessor CPU when the pin changes state. They can be programmed to
interrupt on a rising edge or a falling edge on the pin.
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