Specifications

Section 43. High-Speed PWM

High-Speed PWM

43.10.1 PWM Fault Generated by the Analog Comparator

To use the comparator output as one of the fault/current-limit sources, remap the comparator

output to a general I/O (GPIO) pin and remap one of the external faults as an input to the same

pin. Remapping can be to a GPIO pin or to a virtual pin.

Virtual pins are identical in functionality to all other RPx pins, with the exception of pinouts. The

four virtual pins are internal to the devices and are not connected to a physical device pin. The

comparator output remap to the virtual pin is illustrated in Figure 43-35.

For example, the output of the Analog Comparator and the PWM fault input can be configured

for RP32. This configuration allows the Analog Comparator to trigger PWM faults without the use

of actual physical pin on the device. Refer to the “I/O Ports” chapter in the specific device data

sheet for more details on virtual pins.

Example 43-20 shows the configuration of the Analog Comparator 1 as one of the fault sources

to the PWM that is connected to the fault input pin 1. The following output and input functions are

used:

• Output Function: Analog Comparator 1

• Input Function: PWM Fault Pin 1

Example 43-20: Configuring Analog Comparator as a Fault Source to the PWM

Figure 43-35: Comparator Output Remap to the Virtual Pin

Note: This section only applies to devices with remappable I/O. Refer to the Controller

Family tables in the specific device data sheet for the list of available peripherals.

For devices without remmappable I/O the analog comparators can be directly

assigned as fault source by configuring the FLTSRC<4:0> (FCLCONx<7:3>) bits as

shown in Figure 43-34.

/* Unlock Registers */

__builtin_write_OSCCONL(OSCCON & ~(1<<6));

/* Configure Comparator Output Function */

RPOR16bits.RP32R = 0b100111; /* Assign ACMP1 To Pin RP32 */

/* Configure Fault Input Function */

RPINR29bits.FLT1R=32; /* Assign Fault1 To Pin RP32 */

/* Lock Registers */

__builtin_write_OSCCONL(OSCCON | (1<<6));

Note: The comparator output can also be remapped to a general purpose I/O (GPIO) pin.

FLTSRC<4:0>/CLSRC<4:0>

CMP1x

00000

00001

00010

00100

00101

00110

00111

00011

RPx

Analog Comparator Module

Virtual Pin