PIC16F716-I-P Datasheet, PDF (58/136 Pages) Microchip Technology – 8-bit Flash-based Microcontroller with A/D Converter and Enhanced Capture/Compare/PWM

PIC16F716
8.3.8
ENHANCED PWM AUTO-
SHUTDOWN MODE
The PWM mode supports an Auto-Shutdown mode that
will disable the PWM outputs when an external
shutdown event occurs. Auto-Shutdown mode places
the PWM output pins into a predetermined state. This
mode is used to help prevent the PWM from damaging
the application.
The auto-shutdown sources are selected using the
ECCPASx bits of the ECCPAS register. A shutdown
event may be generated by:
• A logic ‘0’ on the INT pin
• Setting the ECCPASE bit in firmware
When a shutdown event occurs, two things happen:
The ECCPASE bit is set to ‘1’. The ECCPASE will
remain set until cleared in firmware or an auto-restart
occurs (see Section 8.3.9 “Auto-Restart Mode”).
The enabled PWM pins are asynchronously placed in
their shutdown states. The PWM output pins are
grouped into pairs [P1A/P1C] and [P1B/P1D]. The state
of each pin pair is determined by the PSSAC and
PSSBD bits of the ECCPAS register. Each pin pair may
be placed into one of three states:
• Drive logic ‘1’
• Drive logic ‘0’
• Tri-state (high-impedance)
A shutdown condition is indicated by the ECCPASE
(Auto-Shutdown Event Status) bit of the ECCPAS
register. If the bit is a ‘0’, the PWM pins are operating
normally. If the bit is a ‘1’, the PWM outputs are in the
shutdown state. Refer to Figure 8-5.
FIGURE 8-5:
AUTO-SHUTDOWN BLOCK DIAGRAM
ECCPAS<2:0>
111
110
101
100
INT
011
From Comparator C2
010
From Comparator C1
001
000
PRSEN
R
From Data Bus
D
Write to ECCPASE
S
Q ^ECCPASE
PSSAC<0> ₁
P1A_DRV
0
PSSAC<1>
TRISx
PSSBD<0> ₁
P1B_DRV
0
PSSBD<1>
TRISx
PSSAC<0> ₁
P1C_DRV
0
P1A
P1B
PSSAC<1>
TRISx
P1C
PSSBD<0> ₁
P1D_DRV
0
PSSBD<1>
P1D
TRISx
DS41206B-page 56
© 2007 Microchip Technology Inc.