PIC16F877T-20I/PQ Microchip Technology, PIC16F877T-20I/PQ Datasheet - Page 66

• Manufacturer Part Number: PIC16F877T-20I/PQ
• Description: IC,MICROCONTROLLER,8-BIT,PIC CPU,CMOS,QFP,44PIN,PLASTIC
• Manufacturer: Microchip Technology
• Series: PIC® 16Fr

Specifications of PIC16F877T-20I/PQ

• Rohs Compliant: YES
• Core Processor: PIC
• Core Size: 8-Bit
• Speed: 20MHz
• Connectivity: I²C, SPI, UART/USART
• Peripherals: Brown-out Detect/Reset, POR, PWM, WDT
• Number Of I /o: 33
• Program Memory Size: 14KB (8K x 14)
• 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: -40°C ~ 85°C
• Package / Case: 44-MQFP, 44-PQFP
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

PICmicro MID-RANGE MCU FAMILY
3.4
DS31003A-page 3-16
Design Tips
Question 1:
Answer 1:
If the device you are using does not have filtering to the on-chip master clear circuit
ensure that proper external filtering is placed on the MCLR pin to remove narrow pulses. Electri-
cal Specification
Question 2:
Answer 2:
The most common reason for this is that the windowed device (JW) has not had its window cov-
ered. The background light causes the device to power-up in a different state than would typically
be seen in a device where no light is present. In most cases all the General Purpose RAM and
Special Function Registers were not initialized properly.
When my system is subjected to an environment with ESD and EMI, it oper-
ates erratically.
With JW (windowed) devices my system resets and operates properly. With
an OTP device, my system does not operate properly.
parameter 35
specifies the pulse width required to cause a reset.
1997 Microchip Technology Inc.
(Appendix
C),