PIC16F1939-I/P Microchip Technology Inc., PIC16F1939-I/P Datasheet - Page 225

• Manufacturer Part Number: PIC16F1939-I/P
• Description: 28KB Flash, 1KB RAM, 256B EEPROM, LCD, 1.8-5.5V
• Manufacturer: Microchip Technology Inc.

Specifications of PIC16F1939-I/P

• A/d Inputs: 14-Channel, 10-Bit
• Comparators: 2
• Cpu Speed: 8 MIPS
• Eeprom Memory: 256 Bytes
• Input Output: 36
• Interface: I2C/SPI/UART/USART
• Memory Type: Flash
• Number Of Bits: 8
• Package Type: 40-pin PDIP
• Programmable Memory: 28K Bytes
• Ram Size: 1K Bytes
• Speed: 32 MHz
• Temperature Range: –40 to 125 °C
• Timers: 4-8-bit, 1-16-bit
• Voltage, Range: 1.8-5.5 V

FIGURE 22-13:
22.4.3
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
CCPxAS<2:0> bits of the CCPxAS register. A shutdown
event may be generated by:
• A logic ‘0’ on the INT pin
• Comparator Cx
• Setting the CCPxASE bit in firmware
A shutdown condition is indicated by the CCPxASE
(Auto-Shutdown Event Status) bit of the CCPxAS
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.
When a shutdown event occurs, two things happen:
The CCPxASE bit is set to ‘1’. The CCPxASE will
remain set until cleared in firmware or an auto-restart
occurs (see Section 22.4.4 “Auto-Restart Mode”).
The enabled PWM pins are asynchronously placed in
their shutdown states. The PWM output pins are
grouped into pairs [PxA/PxC] and [PxB/PxD]. The state
 2009 Microchip Technology Inc.
Shoot-Through Current
Note 1: All signals are shown as active-high.
External Switch C
External Switch D
2: T
3: T
ENHANCED PWM
AUTO-SHUTDOWN MODE
ON
OFF
Potential
is the turn on delay of power switch QC and its driver.
is the turn off delay of power switch QD and its driver.
PxA
PxB
PxC
PxD
EXAMPLE OF PWM DIRECTION CHANGE AT NEAR 100% DUTY CYCLE
Forward Period
PW
Preliminary
of each pin pair is determined by the PSSxAC and
PSSxBD bits of the CCPxAS register. Each pin pair may
be placed into one of three states:
• Drive logic ‘1’
• Drive logic ‘0’
• Tri-state (high-impedance)
PIC16F193X/LF193X
Note 1: The
t1
2: Writing to the CCPxASE bit is disabled
3: Once the auto-shutdown condition has
level-based signal, not an edge-based
signal. As long as the level is present, the
auto-shutdown will persist.
while
persists.
been removed and the PWM restarted
(either through firmware or auto-restart)
the PWM signal will always restart at the
beginning of the next PWM period.
T
ON
Reverse Period
T
T = T
OFF
auto-shutdown
an
OFF
PW
– T
auto-shutdown
ON
DS41364D-page 225
condition
condition
is
a