PIC18LF24K Datasheet, PDF (280/594 Pages) –

PIC18(L)F26/45/46K40
22.1.9
SETUP FOR PWM OPERATION
USING PWMx PINS
The following steps should be taken when configuring
the module for PWM operation using the PWMx pins:
1. Disable the PWMx pin output driver(s) by setting
the associated TRIS bit(s).
2. Clear the PWMxCON register.
3. Load the PR2 register with the PWM period value.
4. Load the PWMxDCH register and bits <7:6> of
the PWMxDCL register with the PWM duty cycle
value.
5. Configure and start Timer2:
• Clear the TMR2IF interrupt flag bit of the
PIR4 register. See Note 1 below.
• Select the timer clock source to be as
FOSC/4 using the TxCLKCON register. This
is required for correct operation of the
PWM module.
• Configure the T2CKPS bits of the T2CON
register with the Timer2 prescale value.
• Enable Timer2 by setting the T2ON bit of the
T2CON register.
6. Enable PWM output pin and wait until Timer2
overflows, TMR2IF bit of the PIR4 register is set.
See note below.
7. Enable the PWMx pin output driver(s) by clear-
ing the associated TRIS bit(s) and setting the
desired pin PPS control bits.
8. Configure the PWM module by loading the
PWMxCON register with the appropriate values.
Note 1: In order to send a complete duty cycle
and period on the first PWM output, the
above steps must be followed in the order
given. If it is not critical to start with a
complete PWM signal, then move Step 8
to replace Step 4.
2: For operation with other peripherals only,
disable PWMx pin outputs.
22.1.10 SETUP FOR PWM OPERATION TO
OTHER DEVICE PERIPHERALS
The following steps should be taken when configuring
the module for PWM operation to be used by other
device peripherals:
1. Disable the PWMx pin output driver(s) by setting
the associated TRIS bit(s).
2. Clear the PWMxCON register.
3. Load the PR2 register with the PWM period value.
4. Load the PWMxDCH register and bits <7:6> of
the PWMxDCL register with the PWM duty cycle
value.
5. Configure and start Timer2:
• Clear the TMR2IF interrupt flag bit of the
PIR4 register. See Note 1 below.
• Select the timer clock source to be as
FOSC/4 using the TxCLKCON register. This
is required for correct operation of the
PWM module.
• Configure the T2CKPS bits of the T2CON
register with the Timer2 prescale value.
• Enable Timer2 by setting the T2ON bit of the
T2CON register.
6. Enable PWM output pin:
• Wait until Timer2 overflows, TMR2IF bit of the
PIR4 register is set. See Note 1 below.
7. Configure the PWM module by loading the
PWMxCON register with the appropriate values.
Note 1: In order to send a complete duty cycle
and period on the first PWM output, the
above steps must be included in the
setup sequence. If it is not critical to start
with a complete PWM signal on the first
output, then step 6 may be ignored.
 2016 Microchip Technology Inc.
Preliminary
DS40001816C-page 280