The PIC microcontroller contains a processor, memory and input/output ports, and the program is stored in flash ROM memory in numbered locations. The P16F877A stores a maximum of 8096 14-bit instructions in flash ROM, has 368 bytes of RAM and five ports (33 I/O pins). The P16FXXX family uses only 35 instructions, and the program is executed in sequence, unless there is a jump instruction. The program counter tracks the current instruction address. A configuration word is loaded initially to select the clock type and other chip options. The program source code (.ASM) is assembled into machine code (.HEX), downloaded to the chip and the application hardware tested.
PIC microcontroller; microcontroller unit (MCU); 16F877A; ...