PIC16F877-20/P Microchip Technology, PIC16F877-20/P Datasheet - Page 187

• Manufacturer Part Number: PIC16F877-20/P
• Description: IC MCU FLASH 8KX14 EE 40DIP
• Manufacturer: Microchip Technology
• Series: PIC® 16Fr

Specifications of PIC16F877-20/P

• Core Size: 8-Bit
• Program Memory Size: 14KB (8K x 14)
• Core Processor: PIC
• Speed: 20MHz
• Connectivity: I²C, SPI, UART/USART
• Peripherals: Brown-out Detect/Reset, POR, PWM, WDT
• Number Of I /o: 33
• Program Memory Type: FLASH
• Eeprom Size: 256 x 8
• Ram Size: 368 x 8
• Voltage - Supply (vcc/vdd): 4 V ~ 5.5 V
• Data Converters: A/D 8x10b
• Oscillator Type: External
• Operating Temperature: 0°C ~ 70°C
• Package / Case: 40-DIP (0.600", 15.24mm)
• Controller Family/series: PIC16F
• No. Of I/o's: 33
• Eeprom Memory Size: 256Byte
• Ram Memory Size: 368Byte
• Cpu Speed: 20MHz
• No. Of Timers: 3
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• For Use With: 444-1001 - DEMO BOARD FOR PICMICRO MCU
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant, Lead free / RoHS Compliant

12.6
1997 Microchip Technology Inc.
Timer1 Oscillator
A crystal oscillator circuit is built in between pins T1OSI (input) and T1OSO (amplifier output). It
is enabled by setting the T1OSCEN control bit (T1CON<3>). The oscillator is a low power
oscillator, rated up to 200 kHz operation. It will continue to run during SLEEP. It is primarily
intended for a 32 kHz crystal, which is an ideal frequency for real-time keeping.
the capacitor selection for the Timer1 oscillator.
The Timer1 oscillator is identical to the LP oscillator. The user must provide a software time delay
to ensure proper oscillator start-up.
Table 12-1: Capacitor Selection for the Timer1 Oscillator
Crystals Tested:
32.768 kHz
100 kHz
200 kHz
Note 1: Higher capacitance increases the stability of oscillator but also increases the start-up
Note:
2: Since each resonator/crystal has its own characteristics, the user should consult the
Osc Type
time.
resonator/crystal manufacturer for appropriate values of external components.
LP
This allows the counter to operate (increment) when the device is in sleep mode,
which allows Timer1 to be used as a real-time clock.
Epson C-001R32.768K-A
Epson C-2 100.00 KC-P
STD XTL 200.000 kHz
100 kHz
200 kHz
32 kHz
Freq
Section 12. Timer1
33 pF
15 pF
15 pF
C1
DS31012A-page 12-7
20 PPM
20 PPM
20 PPM
Table 12-1
33 pF
15 pF
15 pF
C2
shows
12