CnASM.md

Comparison of Assembly and C in PIC16

ASM

BSF    STATUS, RP0		; TRIS - BANK 1
CLRF   TRISB			; RB AS OUTPUT
BCF    STATUS, RP0		; PORT - BANK 0
MOVLW  0X5B
MOVWF  TRISB

C

TRISB = 0X00;			; PORT B AS OUTPUT
PORTB = 0X5B;			; DIRECT TRANSFER OF DATA

In C, require preprocessor

#include <p16f84a.h>
void main()
{
TRISB = 0;
PORTB = 0b01010101;
}

LED Blink

#include <p16f84a.h>
#include <delay.c>

void main() {
	TRISB = 0;  // TRISB as output

	for(;;) { // forever loop
		RB0 = 1; 		// lights ON
		MsDelay(250);   // from delay.c library, delay in ms
		RB0 = 0;		// lights OFF
		MsDelay(250);
	}
}

In delay.c

void MsDelay(unsigned int itime) {
	unsingned int i, j;
	for (i=0, i<itime, i++) {
		for (j=0; j<1000; j++) // this loop create 1ms delay
	}
}

Send 00 -> FF to Port B

#include <p16f84a.h>

void main() {
	unsigned char i;
	TRISB = 0;
	for (i=0; i<255; i++) {
		PORTB = i;
	}

}

Send "Hello World!"

#include <p16f84a.h>

void main() {
	unsigned char text [] = "Hello World!"; // create a char array
	unsigned char z;

	TRISB = 0;

	for(z=0; z<12; z++) {
		PORTB = text [z];
	}

Inline ASM

#include <p16f84a.h>

void main() {
	unsigned char i;
	TRISB = 0;
	asm {
		BCF    STATUS, RP0		; PORT - BANK 0
		MOVLW  0X5B
		MOVWF  TRISB
	}
}