PIC18F1230 Datasheet, PDF (137/312 Pages) Microchip Technology – 18/20/28-Pin, Enhanced Flash Microcontrollers with nanoWatt Technology, High-Performance PWM and A/D

FIGURE 13-21:
PWM OUTPUT OVERRIDE
EXAMPLE #1
1
2
3
4
5
6
PWM5
PWM4
PWM3
PWM2
PWM1
PWM0
TABLE 13-4: PWM OUTPUT OVERRIDE
EXAMPLE #1
State OVDCOND (POVD) OVDCONS (POUT)
1
00000000b
2
00000000b
3
00000000b
4
00000000b
5
00000000b
6
00000000b
00100100b
00100001b
00001001b
00011000b
00010010b
00000110b
TABLE 13-5: PWM OUTPUT OVERRIDE
EXAMPLE #2
State OVDCOND (POVD) OVDCONS (POUT)
1
00000011b
2
00110000b
3
00111100b
4
00001111b
00000000b
00000000b
00000000b
00000000b
FIGURE 13-22:
PWM OUTPUT OVERRIDE
EXAMPLE #2
1 23 4
PWM5
PWM4
PWM3
PWM2
PWM1
PWM0
PIC18F1230/1330
13.11 PWM Output and Polarity Control
There are three device Configuration bits associated
with the PWM module that provide PWM output pin
control defined in the CONFIG3L register. They are:
• HPOL
• LPOL
• PWMPIN
These three Configuration bits work in conjunction with
the three PWM Enable bits (PWMEN2:PWMEN0) in
the PWMCON0 register. The Configuration bits and
PWM enable bits ensure that the PWM pins are in the
correct states after a device Reset occurs.
13.11.1 OUTPUT PIN CONTROL
The PWMEN2:PWMEN0 control bits enable each
PWM output pin as required in the application.
All PWM I/O pins are general purpose I/O. When a pair
of pins is enabled for PWM output, the PORT and TRIS
registers controlling the pins are disabled. Refer to
Figure 13-23 for details.
13.11.2 OUTPUT POLARITY CONTROL
The polarity of the PWM I/O pins is set during device
programming via the HPOL and LPOL Configuration
bits in the CONFIG3L register. The HPOL Configura-
tion bit sets the output polarity for the high side PWM
outputs: PWM1, PWM3 and PWM5. The polarity is
active-high when HPOL is cleared (= 0) and active-low
when it is set (= 1).
The LPOL Configuration bit sets the output polarity for
the low side PWM outputs: PWM0, PWM2 and PWM4.
As with HPOL, they are active-high when LPOL is
cleared and active-low when set.
All output signals generated by the PWM module are
referenced to the polarity control bits, including those
generated by Fault inputs or manual override (see
Section 13.10 “PWM Output Override”).
The default polarity Configuration bits have the PWM
I/O pins in active-high output polarity.
© 2006 Microchip Technology Inc.
Advance Information
DS39758B-page 135