PIC16F72-I/SP Microchip Technology Inc., PIC16F72-I/SP Datasheet - Page 44

• Manufacturer Part Number: PIC16F72-I/SP
• Description: 28 PIN, 3.5 KB FLASH, 128 RAM, 22 I/O
• Manufacturer: Microchip Technology Inc.

Specifications of PIC16F72-I/SP

• A/d Inputs: 5-Channel, 8-Bit
• Cpu Speed: 5 MIPS
• Eeprom Memory: 0 Bytes
• Input Output: 22
• Interface: I2C/SPI
• Memory Type: Flash
• Number Of Bits: 8
• Package Type: 28-pin SPDIP
• Programmable Memory: 3.5K Bytes
• Ram Size: 128 Bytes
• Speed: 20 MHz
• Timers: 2-8-bit, 1-16-bit
• Voltage, Range: 2-5.5 V
• Lead Free Status / Rohs Status: RoHS Compliant part Electrostatic Device

PIC16F72
Maximum PWM resolution (bits) for a given PWM
frequency is calculated using Equation 8-3.
EQUATION 8-3:
For a sample PWM period and duty cycle calculation,
see the PICmicro™ Mid-Range MCU Reference
Manual (DS33023).
TABLE 8-3:
TABLE 8-4:
DS39597B-page 42
0Bh,8Bh
10Bh,18Bh
0Ch
8Ch
87h
11h
92h
12h
15h
16h
17h
Legend:
Timer Prescaler (1, 4, 16)
PR2 Value
Maximum Resolution (bits)
Address
Note:
PWM Maximum Resolution =
x = unknown, u = unchanged, - = unimplemented, read as ‘0’. Shaded cells are not used by PWM and Timer2.
INTCON
PIR1
PIE1
TRISC
TMR2
PR2
T2CON
CCPR1L
CCPR1H
CCP1CON
If the PWM duty cycle value is longer than
the PWM period, the CCP1 pin will not be
cleared.
Name
PWM Frequency
EXAMPLE PWM FREQUENCIES AND RESOLUTIONS AT 20 MHz
REGISTERS ASSOCIATED WITH PWM AND TIMER2
PORTC Data Direction Register
Timer2 Module Register
Timer2 Module Period Register
Capture/Compare/PWM Register1 (LSB)
Capture/Compare/PWM Register1 (MSB)
Bit 7
PWM MAX RESOLUTION
GIE
—
—
—
—
TOUTPS3 TOUTPS2 TOUTPS1 TOUTPS0 TMR2ON T2CKPS1 T2CKPS0 -000 0000 -000 0000
PEIE
ADIF
ADIE
Bit 6
—
log ( F
log(2)
F
PWM
OSC
TMR0IE
CCP1X
Bit 5
—
—
)
bits
1.22 kHz 4.88 kHz 19.53 kHz 78.12 kHz 156.3 kHz 208.3 kHz
0xFF
CCP1Y
16
10
INTE
Bit 4
—
—
CCP1M3 CCP1M2 CCP1M1 CCP1M0 --00 0000 --00 0000
0xFF
SSPIF
SSPIE
RBIE
10
Bit 3
4
8.3.3
The following steps should be taken when configuring
the CCP module for PWM operation:
1.
2.
3.
4.
5.
Set the PWM period by writing to the PR2 register.
Set the PWM duty cycle by writing to the
CCPR1L register and CCP1CON<5:4> bits.
Make the CCP1 pin an output by clearing the
TRISC<2> bit.
Set the TMR2 prescale value and enable Timer2
by writing to T2CON.
Configure the CCP1 module for PWM operation.
TMR0IF
CCP1IF
CCP1IE
Bit 2
0xFF
10
1
SET-UP FOR PWM OPERATION
TMR2IE
TMR2IF
INTF
Bit 1
0x3F
1
8
 2002 Microchip Technology Inc.
TMR1IE -0-- 0000 0000 0000
TMR1IF -0-- 0000 0000 0000
RBIF
Bit 0
0x1F
0000 000x 0000 000u
1111 1111 1111 1111
0000 0000 0000 0000
1111 1111 1111 1111
xxxx xxxx uuuu uuuu
xxxx xxxx uuuu uuuu
POR, BOR
1
7
Value on
0x17
5.5
Value on
RESETS
all other
1