PIC16LF1517-E/PT Microchip Technology, PIC16LF1517-E/PT Datasheet - Page 181

• Manufacturer Part Number: PIC16LF1517-E/PT
• Description: 40-pin, 14KB Flash, 512B RAM, 10-bit ADC, 2xCCP, SPI, MI2C, EUSART, 1.8V-3.6V 44
• Manufacturer: Microchip Technology
• Series: PIC® XLP™ 16Fr

Specifications of PIC16LF1517-E/PT

• Core Processor: PIC
• Core Size: 8-Bit
• Speed: 20MHz
• Connectivity: I²C, LIN, SPI, UART/USART
• Peripherals: Brown-out Detect/Reset, POR, PWM, WDT
• Number Of I /o: 36
• Program Memory Size: 14KB (8K x 14)
• Program Memory Type: FLASH
• Ram Size: 512 x 8
• Voltage - Supply (vcc/vdd): 1.8 V ~ 3.6 V
• Data Converters: A/D 28x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 125°C
• Package / Case: *
• Processor Series: PIC16LF151x
• Core: PIC
• Data Bus Width: 8 bit
• Data Ram Size: 512 B
• Interface Type: I2C, SPI, USART
• Maximum Clock Frequency: 20 MHz
• Number Of Programmable I/os: 36
• Number Of Timers: 3
• Operating Supply Voltage: 1.8 V to 3.6 V
• Maximum Operating Temperature: + 125 C
• Mounting Style: SMD/SMT
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -
• Lead Free Status / Rohs Status: Details

20.3.2
The following steps should be taken when configuring
the CCP module for standard PWM operation:
1.
2.
3.
4.
5.
6.
20.3.3
The PWM standard mode makes use of the 8-bit
Timer2 timer resources to specify the PWM period.
20.3.4
The PWM period is specified by the PR2 register of
Timer2. The PWM period can be calculated using the
formula of
EQUATION 20-1:
 2010 Microchip Technology Inc.
Note:
Disable the CCPx pin output driver by setting the
associated TRIS bit.
Load the PR2 register with the PWM period
value.
Configure the CCP module for the PWM mode
by loading the CCPxCON register with the
appropriate values.
Load the CCPRxL register and the DCxBx bits
of the CCPxCON register, with the PWM duty
cycle value.
Configure and start Timer2:
• Clear the TMR2IF interrupt flag bit of the
• Configure the T2CKPS bits of the T2CON
• Enable the Timer by setting the TMR2ON
Enable PWM output pin:
• Wait until the Timer overflows and the
• Enable the CCPx pin output driver by clear-
Note 1:
PWM Period
PIRx register. See Note below.
register with the Timer prescale value.
bit of the T2CON register.
TMR2IF bit of the PIR1 register is set. See
Note below.
ing the associated TRIS bit.
Equation
SETUP FOR PWM OPERATION
In order to send a complete duty cycle and
period on the first PWM output, the above
steps must be included in the setup
sequence. If it is not critical to start with a
complete PWM signal on the first output,
then step 6 may be ignored.
TIMER2 TIMER RESOURCE
PWM PERIOD
T
OSC
=
20-1.
(TMR2 Prescale Value)

PWM PERIOD
= 1/F

PR2
OSC

+
1
 4 T


OSC

Preliminary
When TMR2 is equal to PR2, the following three events
occur on the next increment cycle:
• TMR2 is cleared
• The CCPx pin is set. (Exception: If the PWM duty
• The PWM duty cycle is latched from CCPRxL into
20.3.5
The PWM duty cycle is specified by writing a 10-bit
value to multiple registers: CCPRxL register and
DCxB<1:0> bits of the CCPxCON register. The
CCPRxL contains the eight MSbs and the DCxB<1:0>
bits of the CCPxCON register contain the two LSbs.
CCPRxL and DCxB<1:0> bits of the CCPxCON
register can be written to at any time. The duty cycle
value is not latched into CCPRxH until after the period
completes (i.e., a match between PR2 and TMR2
registers occurs). While using the PWM, the CCPRxH
register is read-only.
Equation 20-2
width.
Equation 20-3
ratio.
EQUATION 20-2:
EQUATION 20-3:
The CCPRxH register and a 2-bit internal latch are
used to double buffer the PWM duty cycle. This double
buffering is essential for glitchless PWM operation.
The 8-bit timer TMR2 register is concatenated with
either the 2-bit internal system clock (F
the prescaler, to create the 10-bit time base. The system
clock is used if the Timer2 prescaler is set to 1:1.
When the 10-bit time base matches the CCPRxH and
2-bit latch, then the CCPx pin is cleared (see
Figure
cycle = 0%, the pin will not be set.)
CCPRxH.
Note:
PIC16(L)F1516/7/8/9
Duty Cycle Ratio
Pulse Width
20-4).
The Timer postscaler (see
“Timer2
determination of the PWM frequency.
PWM DUTY CYCLE
is used to calculate the PWM duty cycle
is used to calculate the PWM pulse
=

T
=
CCPRxL:CCPxCON<5:4>
OSC
Operation”) is not used in the
PULSE WIDTH
DUTY CYCLE RATIO

---------------------------------------------------------------------- -
CCPRxL:CCPxCON<5:4>

(TMR2 Prescale Value)
4 PR2

DS41452A-page 181
+
OSC
1
Section 19.1

), or 2 bits of


