PIC16F877-20/P Microchip Technology, PIC16F877-20/P Datasheet - Page 486

• 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

PICmicro MID-RANGE MCU FAMILY
26.1
DS31026A-page 26-2
Introduction
The Watchdog Timer (WDT) is a free running on-chip RC oscillator which does not require any
external components. The block diagram is shown in
from the device RC oscillator of the OSC1/CLKIN pin. This means that the WDT will run, even if
the clock on the OSC1 and OSC2 pins has been stopped, for example, by execution of a
instruction.
The Watchdog Timer (WDT) is enabled/disabled by a device configuration bit. If the WDT is
enabled, software execution may not disable this function.
Figure 26-1: Watchdog Timer Block Diagram
WDT Timer
Enable Bit
WDT
From TMR0 Clock Source
Note: PSA and PS2:PS0 are bits in the OPTION register.
0
1
PSA
M
U
X
0
Time-out
Figure
8 - to - 1 MUX
MUX
WDT
Postscaler
1
26-1. This RC oscillator is separate
8
1997 Microchip Technology Inc.
PSA
To TMR0
PS2:PS0
SLEEP