Microchip PIC

Cautions

Config

• NEVER disable the PIC's /MCLR (Reset) pin function
• NEVER program a PIC "in circuit" with ANY other connections to the target board

Circuit Design

• ALWAYS set MCLRE_ON in the config options and have MCLR pin with a 10K pull-up resistor to Vdd.

Initialization

• ALWAYS set the input pins and clear the output pins, excepting UART TX/RX.

i.e. SDO should have TRISX bit cleared, SDI should have TRISX bit set.

Configuration Fuses

HI-TECH PICC (MPLAB IDE v8.x)

__CONFIG(1,HS&CPUDIV1) ;  // Conf Reg 1: Use external crystal 4MHz
__CONFIG(2,WDTDIS) ;      // Conf Reg 2: Watchdog off
__CONFIG(3,PBADDIS) ;     // Conf Reg 3: Configure PORTB<4:0> pins as digital I/O on Reset
__CONFIG(4,XINSTDIS) ;    // Conf Reg 4: Extended CPU Enable Disabled

MPLAB XC (MPLAB X v2.x/v3.x)

#pragma config PLLDIV = 1          // No prescale (4 MHz oscillator input drives PLL directly)
#pragma config WDT = OFF           // Watchdog off
#pragma config PBADEN = OFF        // Configure PORTB<4:0> pins as digital I/O on Reset
#pragma config CPUDIV = OSC1_PLL2  // [OSC1/OSC2 Src: /1][96 MHz PLL Src: /2]
#pragma config FOSC = HS           // HS oscillator, HS used by USB

IDEs

• MPLAB - Discontinued Microchip's IDE
• MPLAB X - Official's Microchip IDE
• MPIDE - Arduino like IDE for ChipKit & Fubarino