PIC12F609-I/PQTP MICROCHIP [Microchip Technology], PIC12F609-I/PQTP Datasheet - Page 89

• Manufacturer Part Number: PIC12F609-I/PQTP
• Description: 8-Pin Flash-Based, 8-Bit CMOS Microcontrollers
• Manufacturer: MICROCHIP [Microchip Technology]

10.4.3
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
• Comparator
• Setting the ECCPASE bit in firmware
FIGURE 10-10:
© 2006 Microchip Technology Inc.
From Comparator
INT
ENHANCED PWM AUTO-
SHUTDOWN MODE
ECCPAS<2:0>
AUTO-SHUTDOWN BLOCK DIAGRAM
111
110
101
100
011
010
001
000
From Data Bus
Write to ECCPASE
PRSEN
PIC12F609/615/12HV609/615
Preliminary
R
D
Q
S
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 1.
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 10.4.4 “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)
ECCPASE
PSSAC<1>
PSSBD<1>
PSSAC<0>
P1A_DRV
PSSBD<0>
P1B_DRV
TRISx
TRISx
1
0
1
0
DS41302A-page 87
P1A
P1B