PIC16LF1938-I/MV Microchip Technology, PIC16LF1938-I/MV Datasheet - Page 224

• Manufacturer Part Number: PIC16LF1938-I/MV
• Description: IC MCU 8BIT 28KB FLASH 28UQFN
• Manufacturer: Microchip Technology
• Series: PIC® XLP™ 16Fr

Specifications of PIC16LF1938-I/MV

• Core Processor: PIC
• Core Size: 8-Bit
• Speed: 32MHz
• Connectivity: I²C, LIN, SPI, UART/USART
• Peripherals: Brown-out Detect/Reset, LCD, POR, PWM, WDT
• Number Of I /o: 25
• Program Memory Size: 28KB (16K x 14)
• Program Memory Type: FLASH
• Eeprom Size: 256 x 8
• Ram Size: 1K x 8
• Voltage - Supply (vcc/vdd): 1.8 V ~ 3.6 V
• Data Converters: A/D 11x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 28-UFQFN Exposed Pad
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

PIC16(L)F1938/9
23.4.3
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
• A logic ‘1’ on a Comparator (Cx) output
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
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
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)
FIGURE 23-14:
DS41574A-page 224
Shutdown
PWM
CCPxASE bit
ENHANCED PWM
AUTO-SHUTDOWN MODE
Section 23.4.4 “Auto-Restart
Activity
Event
PWM AUTO-SHUTDOWN WITH FIRMWARE RESTART (PXRSEN = 0)
Overflow
Timer
Start of
PWM Period
PWM Period
(Auto-Shutdown)
Mode”).
Event Occurs
Missing Pulse
Overflow
Shutdown
Timer
Preliminary
Event Clears
Overflow
Shutdown
Timer
Note 1: The
2: Writing to the CCPxASE bit is disabled
3: Once the auto-shutdown condition has
4: Prior to an auto-shutdown event caused
Missing Pulse
(CCPxASE not clear)
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.
by a comparator output or INT pin event,
a software shutdown can be triggered in
firmware by setting the CCPxASE bit of
the
Auto-Restart feature tracks the active sta-
tus of a shutdown caused by a compara-
tor output or INT pin event only. If it is
enabled at this time, it will immediately
clear this bit and restart the ECCP mod-
ule at the beginning of the next PWM
period.
Overflow
Cleared by
CCPxASE
Firmware
Timer
CCPxAS
auto-shutdown
an
PWM
Resumes
 2011 Microchip Technology Inc.
auto-shutdown
register
Overflow
condition
Timer
to
‘1’.
condition
is
The
a