Q.Explain the core features of PIC microcontroller.

The popularity of PIC microcontrollers comes from nine core features that together give them protection, simplicity, speed, strong I/O, interrupts, timers, easy programming and flexible memory. …

[!TLDR]

PIC microcontrollers are widely used because of nine core features: integrated protection, a 35-instruction set, high speed, powerful pin control, up to 12 interrupts, three timers, two-pin serial programming, flexible EPROM/OTP/ROM options and easy I/O expansion.

The following core features account for the wide popularity of PICs:

1. Integration of operational features: power-on reset and brown-out protection ensure the chip operates only when the supply voltage is within specification; a watchdog timer resets the PIC if the chip ever malfunctions and deviates from its normal operation; there are four clock oscillators (any one selectable), including a low-cost RC oscillator and a high-accuracy crystal oscillator; and a variety of low-power options are supported.
2. Instruction set simplicity: the instruction set consists of just 35 instructions, which makes the device easy to learn and program.
3. Speed: when operated at its maximum clock rate, a PIC executes most of its instructions in 0.2 $\mu s$, i.e. five instructions per microsecond.
4. Powerful output pin control: a single instruction can select and drive a single output pin high or low in its 0.2 $\mu s$ execution time, and the pin can drive a load of up to 25 mA.
5. Interrupt control: up to 12 independent sources can control when the CPU will deal with each source.
6. Programmable timer options: three versatile timers can characterise inputs, control outputs and provide internal timing for program execution.
7. Serial programming via two pins: the simplicity of the programming hardware means PIC programmers are available for under USD 100.
8. EPROM/OTP/ROM options: development is supported by ultraviolet-erasable, programmable (EPROM) ports, and both small and large production runs are supported by low-cost one-time-programmable (OTP) ports.
9. I/O port expansion: the built-in serial peripheral interface can use standard 16-pin shift-register ports to add any number of I/O pins. …