PIC18C801-I/L Microchip Technology, PIC18C801-I/L Datasheet - Page 146

• Manufacturer Part Number: PIC18C801-I/L
• Description: IC,MICROCONTROLLER,8-BIT,PIC CPU,CMOS,LDCC,84PIN,PLASTIC
• Manufacturer: Microchip Technology
• Series: PIC® 18Cr

Specifications of PIC18C801-I/L

• Rohs Compliant: YES
• Core Processor: PIC
• Core Size: 8-Bit
• Speed: 25MHz
• Connectivity: EBI/EMI, I²C, SPI, UART/USART
• Peripherals: Brown-out Detect/Reset, LVD, POR, PWM, WDT
• Number Of I /o: 37
• Program Memory Type: ROMless
• Ram Size: 1.5K x 8
• Voltage - Supply (vcc/vdd): 4.2 V ~ 5.5 V
• Data Converters: A/D 12x10b
• Oscillator Type: External
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 84-PLCC
• Processor Series: PIC18C
• Core: PIC
• Data Bus Width: 8 bit
• Data Ram Size: 1.5 KB
• Interface Type: 3-Wire, I2C, SPI, USART
• Maximum Clock Frequency: 25 MHz
• Number Of Programmable I/os: 47
• Number Of Timers: 1 x 16 bit
• Operating Supply Voltage: 2 V to 5.5 V
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• 3rd Party Development Tools: 52715-96, 52716-328, 52717-734, 52712-325, EWPIC18
• Development Tools By Supplier: DV164005, ICE4000, DV164136
• Minimum Operating Temperature: - 40 C
• On-chip Adc: 10 bit
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• For Use With: AC164310 - MODULE SKT FOR PM3 84PLCCXLT84L1 - SOCKET TRANSITION ICE 84PLCCAC174012 - MODULE SKT PROMATEII 84PLCC
• Eeprom Size: -
• Program Memory Size: -
• Lead Free Status / Rohs Status: Details
• Other names: PIC18C801-I/LR; PIC18C801-I/LR; PIC18C801I/L

PIC18C601/801
14.5
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 14-3 shows a simplified block diagram of the
CCP module in PWM mode.
For a step-by-step procedure on how to setup the CCP
module for PWM operation, see Section 14.5.3.
FIGURE 14-3:
A PWM output (Figure 14-4) 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 14-4:
DS39541A-page 146
Note:
Note 1: 8-bit timer is concatenated with 2-bit internal Q clock, or
CCPR1L (Master)
CCPR1H (Slave)
Comparator
Duty Cycle Registers
TMR2 = PR2
PR2
TMR2
Comparator
PWM Mode
2 bits of the prescaler, to create 10-bit time-base.
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)
TMR2 = Duty Cycle
Clear Timer,
CCP1 pin and
latch D.C.
SIMPLIFIED PWM BLOCK
DIAGRAM
PWM OUTPUT
TMR2 = PR2
CCP1CON<5:4>
R
S
Q
TRISC<2>
Advance Information
RC2/CCP1
14.5.1
The PWM period is specified by writing to the PR2
register. The PWM period can be calculated by the
formula:
where 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 CCP1 pin is set (exception: if PWM duty
• The PWM duty cycle is latched from CCPR1L into
14.5.2
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.
The maximum PWM resolution (bits) for a given PWM
frequency is given by the equation:
cycle = 0%, the CCP1 pin will not be set)
CCPR1H
Note:
Note:
PWM period =
PWM duty cycle =
PWM Resolution (max)
The Timer2 postscaler (see Section 12.1)
is not used in the determination of the
PWM frequency. The postscaler could be
used to have a servo update rate at a dif-
ferent frequency than the PWM output.
If the PWM duty cycle value is longer than
the PWM period, the CCP1 pin will not be
cleared.
PWM PERIOD
PWM DUTY CYCLE
[(PR2) + 1] • 4 • T
(TMR2 prescale value)
(CCPR1L:CCP1CON<5:4>) •
T
OSC
2001 Microchip Technology Inc.
=
• (TMR2 prescale value)
log
-----------------------------bits
log
---------------
F
F
PWM
OSC
2
OSC
•