PIC18F85K22-I/PT Microchip Technology, PIC18F85K22-I/PT Datasheet - Page 255

• Manufacturer Part Number: PIC18F85K22-I/PT
• Description: IC, 8BIT MCU, PIC18F, 64MHZ, TQFP-80
• Manufacturer: Microchip Technology
• Series: PIC® XLP™ 18Fr

Specifications of PIC18F85K22-I/PT

• Controller Family/series: PIC18
• No. Of I/o's: 69
• Eeprom Memory Size: 1KB
• Ram Memory Size: 2KB
• Cpu Speed: 64MHz
• No. Of Timers: 8
• Core Size: 8 Bit
• Program Memory Size: 32KB
• Core Processor: PIC
• Speed: 64MHz
• Connectivity: EBI/EMI, I²C, LIN, SPI, UART/USART
• Peripherals: Brown-out Detect/Reset, LVD, POR, PWM, WDT
• Number Of I /o: 69
• Program Memory Type: FLASH
• Eeprom Size: 1K x 8
• Ram Size: 2K x 8
• Voltage - Supply (vcc/vdd): 1.8 V ~ 5.5 V
• Data Converters: A/D 24x12b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 80-TQFP
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

19.4
In Pulse-Width Modulation (PWM) mode, the CCP4 pin
produces up to a 10-bit resolution PWM output. Since
the CCP4 pin is multiplexed with a PORTC or PORTE
data latch, the appropriate TRIS bit must be cleared to
make the CCP4 pin an output.
Figure 19-3
ECCP1 module in PWM mode.
For a step-by-step procedure on how to set up the CCP
module for PWM operation, see
“Setup for PWM
FIGURE 19-3:
 2009-2011 Microchip Technology Inc.
Note 1:
2:
Note:
CCPR4H (Slave)
Duty Cycle Registers
Comparator
CCPR4L
TMR2
PR2
Comparator
PWM Mode
The 8-bit TMR2 value is concatenated with the 2-bit
internal Q clock, or 2 bits of the prescaler, to create
the 10-bit time base.
CCP4 and its appropriate timers are used as an
example. For details on all of the CCP modules and
their timer assignments, see
Table
Clearing the CCP4CON register will force
the RC1 or RE7 output latch (depending
on device configuration) to the default low
level. This is not the PORTC or PORTE
I/O data latch.
shows a simplified block diagram of the
19-3.
(Note 1)
(Note 2)
(Note 2)
Operation”.
Clear Timer,
ECCP1 Pin and
Latch D.C.
SIMPLIFIED PWM BLOCK
DIAGRAM
CCP4CON<5:4>
R
S
Table 19-2
Q
TRISC<2>
Section 19.4.3
and
RC2/ECCP1
PIC18F87K22 FAMILY
A PWM output
and a time that the output stays high (duty cycle). The
frequency of the PWM is the inverse of the period
(1/period).
FIGURE 19-4:
19.4.1
The PWM period is specified by writing to the PR2
register. The PWM period can be calculated using the
following formula:
EQUATION 19-1:
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 CCP4 pin is set
• The PWM duty cycle is latched from CCPR4L into
(An exception: If PWM duty cycle = 0%, the CCP4
pin will not be set)
CCPR4H
Note:
PWM Period = [(PR2) + 1] • 4 • T
TMR2 = PR2
Duty Cycle
PWM PERIOD
The
Section 15.0 “Timer2
used in the determination of the PWM
frequency. The postscaler could be used
to have a servo update rate at a different
frequency than the PWM output.
(Figure
Period
TMR2 = Duty Cycle
Timer2
(TMR2 Prescale Value)
PWM OUTPUT
19-4) has a time base (period)
TMR2 = PR2
postscalers
Module”) are not
DS39960D-page 255
OSC
•
(see