PIC16F887-E/P Microchip Technology Inc., PIC16F887-E/P Datasheet - Page 132

• Manufacturer Part Number: PIC16F887-E/P
• Description: 40 PIN, 14KB FLASH, 368 RAM, 36 I/O, PDIP
• Manufacturer: Microchip Technology Inc.

Specifications of PIC16F887-E/P

• A/d Inputs: 14-Channel, 10-Bit
• Comparators: 2
• Cpu Speed: 5 MIPS
• Eeprom Memory: 256 Bytes
• Frequency: 20 MHz
• Input Output: 35
• Interface: I2C/SPI/USART
• Memory Type: Flash
• Number Of Bits: 8
• Package Type: 40-pin PDIP
• Programmable Memory: 14K Bytes
• Ram Size: 368 Bytes
• Resistance, Drain To Source On: Bytes
• Serial Interface: MSSP or EUSART
• 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

PIC16F882/883/884/886/887
11.5.3
The resolution determines the number of available duty
cycles for a given period. For example, a 10-bit resolution
will result in 1024 discrete duty cycles, whereas an 8-bit
resolution will result in 256 discrete duty cycles.
The maximum PWM resolution is 10 bits when PR2 is
255. The resolution is a function of the PR2 register
value as shown by Equation 11-4.
TABLE 11-3:
TABLE 11-4:
DS41291E-page 130
Timer Prescale (1, 4, 16)
PR2 Value
Maximum Resolution (bits)
Timer Prescale (1, 4, 16)
PR2 Value
Maximum Resolution (bits)
PWM Frequency
PWM Frequency
PWM RESOLUTION
EXAMPLE PWM FREQUENCIES AND RESOLUTIONS (F
EXAMPLE PWM FREQUENCIES AND RESOLUTIONS (F
1.22 kHz
1.22 kHz
0xFF
0x65
16
10
16
8
4.88 kHz
4.90 kHz
0xFF
0x65
10
4
4
8
19.53 kHz
19.61 kHz
EQUATION 11-4:
0xFF
Note:
0x65
10
1
1
8
Resolution
If the pulse width value is greater than the
period the assigned PWM pin(s) will
remain unchanged.
78.12 kHz
76.92 kHz
0x3F
0x19
1
8
1
6
OSC
OSC
=
PWM RESOLUTION
log
----------------------------------------- - bits
© 2008 Microchip Technology Inc.
= 20 MHz)
= 8 MHz)
[
4 PR2
153.85 kHz
log
156.3 kHz
(
0x0C
0x1F
2 ( )
1
7
1
5
+
1
)
]
208.3 kHz
200.0 kHz
0x17
0x09
6.6
1
1
5