Digilent 410-297P-KIT - Manual (Page 16)

ChipKIT MX3 Board Reference Manual
Copyright Digilent, Inc. All rights reserved.
Other product and company names mentioned may be trademarks of their respective owners.
Page 16 of 25
For detailed information on the operation of the PIC32 timers, refer to the PIC32 Family Reference Manual, Section
14, Timers.
Control and operation of the timers is not explicitly provided in the current version of the MPIDE software. This
capability will be added in a future version of the software. Timers are used implicitly by various core functions and
libraries, however.
12 Output Compare
The PIC32 microcontroller provides five output compare units that can be used to control the timing of state
changes on certain output pins or to generate pulse width modulated (PWM) outputs.
Each output compare unit works with a particular output pin (OC1-OC5). It can be programmed to control the pin
in any of the following ways:
• PWM output
• Generate continuous pulses
• Generate a single pulse
• Toggle the output pin
• Generate falling edge
• Generate rising edge
The output compare units work in conjunction with a timer. Either Timer2 or Timer3 can be used with any of the
five output compare units.
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.