Programming 8-bit PIC Microcontrollers in C

1.2. PIC16 MCU Configuration

• Clock oscillator types

• Watchdog, power-up, brown-out timers

• Low-voltage programming

• Code protection

• In-circuit debug mode

When programming the PIC microcontroller, certain operational modes must be set prior to the main program download. These are controlled by individual bits in a special configuration register separated from the main memory block. The main options are as follows.

Clock Options

The ‘877 chip has two main clock modes, CR and XT. The CR mode needs a simple capacitor and resistor circuit attached to CLKIN, whose time constant (C × R) determines the clock period. R should be between 3 k and 100 k, and C greater than 20 pF.For example, if R=10 kΩ and C=10 nF, the clock period will be around 2×C×R=200 ...