PIC16F87-I/ML Microchip Technology, PIC16F87-I/ML Datasheet - Page 138

• Manufacturer Part Number: PIC16F87-I/ML
• Description: IC MCU FLASH 4KX14 EEPROM 28QFN
• Manufacturer: Microchip Technology
• Series: PIC® 16Fr

Specifications of PIC16F87-I/ML

• Core Size: 8-Bit
• Program Memory Size: 7KB (4K x 14)
• Oscillator Type: Internal
• Core Processor: PIC
• Speed: 20MHz
• Connectivity: I²C, SPI, UART/USART
• Peripherals: Brown-out Detect/Reset, POR, PWM, WDT
• Number Of I /o: 16
• Program Memory Type: FLASH
• Eeprom Size: 256 x 8
• Ram Size: 368 x 8
• Voltage - Supply (vcc/vdd): 4 V ~ 5.5 V
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 28-VQFN Exposed Pad, 28-HVQFN, 28-SQFN, 28-DHVQFN
• Controller Family/series: PIC16F
• No. Of I/o's: 16
• Eeprom Memory Size: 256Byte
• Ram Memory Size: 368Byte
• Cpu Speed: 20MHz
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• For Use With: XLT28QFN3 - SOCKET TRAN ICE 18DIP/28QFNAC164322 - MODULE SOCKET MPLAB PM3 28/44QFNAC164033 - ADAPTER 28QFN TO 18DIPDV007003 - PROGRAMMER UNIVERSAL PROMATE II
• Data Converters: -
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant, Lead free / RoHS Compliant

PICmicro MID-RANGE MCU FAMILY
8.7
DS31008A-page 8-16
Design Tips
Question 1:
Answer 1:
Assuming that the algorithm is correct and that interrupts are enabled during the algorithm,
ensure that are registers that are used by the algorithm and by the interrupt service routine are
saved and restored. If not some registers may be corrupted by the execution of the ISR.
Question 2:
Answer 2:
If interrupts are being used, ensure that the interrupt flag is cleared after servicing that interrupt
(but before executing the RETFIE instruction). If the interrupt flag remains set when the RETFIE
instruction is executed, program execution immediately returns to the interrupt vector, since there
is an outstanding enabled interrupt.
An algorithm does not give the correct results.
My system seems to lock up.
1997 Microchip Technology Inc.