PIC16LC65-04I/L Microchip Technology, PIC16LC65-04I/L Datasheet - Page 80

• Manufacturer Part Number: PIC16LC65-04I/L
• Description: IC MIC CTL 4K LP OTP IT 44PLCC
• Manufacturer: Microchip Technology
• Series: PIC® 16Cr

Specifications of PIC16LC65-04I/L

• Core Processor: PIC
• Core Size: 8-Bit
• Speed: 4MHz
• Connectivity: I²C, SPI, UART/USART
• Peripherals: POR, PWM, WDT
• Number Of I /o: 33
• Program Memory Size: 7KB (4K x 14)
• Program Memory Type: OTP
• Ram Size: 192 x 8
• Voltage - Supply (vcc/vdd): 3 V ~ 6 V
• Oscillator Type: External
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 44-PLCC
• Lead Free Status / RoHS Status: Request inventory verification / Request inventory verification
• Eeprom Size: -
• Data Converters: -

PIC16C6X
10.3
In Pulse Width Modulation (PWM) mode, the CCP1 pin
produces up to a 10-bit resolution PWM output. Since
the CCP1 pin is multiplexed with the PORTC data latch,
the TRISC<2> bit must be cleared to make the CCP1
pin an output.
Figure 10-4 shows a simplified block diagram of the
CCP module in PWM mode.
For a step by step procedure on how to set up the CCP
module for PWM operation, see Section 10.3.3.
FIGURE 10-4: SIMPLIFIED PWM BLOCK
A PWM output (Figure 10-5) has a time base (period)
and a time that the output stays high (duty cycle). The
frequency of the PWM is the inverse of the period
(1/period).
FIGURE 10-5: PWM OUTPUT
DS30234D-page 80
Applicable Devices
61 62 62A R62 63 R63 64 64A R64 65 65A R65 66 67
Note 1: 8-bit timer is concatenated with 2-bit internal Q clock
Note:
CCPR1L
CCPR1H (Slave)
Comparator
Duty cycle registers
TMR2 = PR2
PR2
or 2 bits of the prescaler to create 10-bit time-base.
TMR2
Comparator
PWM Mode
Duty Cycle
Clearing the CCP1CON register will force
the CCP1 PWM output latch to the default
low level. This is not the PORTC I/O data
latch.
Period
(Note 1)
DIAGRAM
TMR2 = Duty Cycle
Clear Timer,
CCP1 pin and
latch D.C.
TMR2 = PR2
CCP1CON<5:4>
R
S
Q
TRISC2
RC2/CCP1
10.3.1
The PWM period is specified by writing to the PR2 reg-
ister. The PWM period can be calculated using the fol-
lowing formula:
PWM frequency is defined as 1 / [PWM period].
When TMR2 is equal to PR2, the following three events
occur on the next increment cycle:
• TMR2 is cleared
• The PWM duty cycle is latched from CCPR1L into
• The CCP1 pin is set (exception: if PWM duty
10.3.2
The PWM duty cycle is specified by writing to the
CCPR1L register and to the CCP1CON<5:4> bits. Up
to 10-bit resolution is available: the CCPR1L contains
the eight MSbs and the CCP1CON<5:4> contains the
two LSbs. This 10-bit value is represented by
CCPR1L:CCP1CON<5:4>. The following equation is
used to calculate the PWM duty cycle in time:
CCPR1L and CCP1CON<5:4> can be written to at any
time, but the duty cycle value is not latched into
CCPR1H until after a match between PR2 and TMR2
occurs (i.e., the period is complete). In PWM mode,
CCPR1H is a read-only register.
The CCPR1H 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.
When the CCPR1H and 2-bit latch match TMR2 con-
catenated with an internal 2-bit Q clock or 2 bits of the
TMR2 prescaler, the CCP1 pin is cleared.
Maximum PWM resolution (bits) for a given PWM
frequency:
CCPR1H
cycle = 0%, the CCP1 pin will not be set)
Note:
Note:
PWM duty cycle = (CCPR1L:CCP1CON<5:4>) •
PWM period = [(PR2) + 1] • 4 • T
PWM PERIOD
PWM DUTY CYCLE
The Timer2 postscaler (see Section 9.1) is
not used in the determination of the PWM
frequency. The postscaler could be used to
have a servo update rate at a different fre-
quency than the PWM output.
If the PWM duty cycle value is longer than
the PWM period the CCP1 pin will not be
forced to the low level.
=
(TMR2 prescale value)
log
log(2)
Tosc • (TMR2 prescale value)
(
F
F
1997 Microchip Technology Inc.
PWM
OSC
)
OSC
bits
•