*		Lorenzo Windmoller, Nicolas Salles, Tómas Onofrio, Vitor Espindola
* 
*		Program "ContaPares" with goal to count the quantity of even numbers
*		in a vector with a static size.
*	
*		Code in C Language is:
*
*		1. int conta_pares(int *vector, int size) {
*    		2. 	int count = 0;
*    		3.	for (int i = 0; i < size; i++) {
*       	4. 		if (vector[i] % 2 == 0)
*       	5.     			count++;
*    		6.	}
*    		7.	return count;
*		8. }
*

* =============================================================================================

		ORG	$0000		;define start address
	
* =============================================================================================
	
size		EQU	&20		;define label size with 20
	
vector		RMB 	size		;declare vector with size 20, for 10 numbers w/ 2 bytes

count		RMB	&02		;declare counter with 2 bytes

pos		RMB	&02		;declare position controller with 2 bytes

* =============================================================================================

initialize	CLR	count		;clear content in count address

		CLR	pos		;clear content in pos address

* =============================================================================================

load_values 	LDX	#vector		;load index register X with vector address
		
		LDD	#&20		;load accumulator D with '0d20'

		STD	0,x		;store accumulator D in position 0-1 of the vector
		
		LDD	#&53		;load accumulator D with '0d53'

		STD	2,x		;store accumulator D in position 2-3 of the vector
	
		LDD	#&11		;load accumulator D with '0d11'
	
		STD	4,x		;store accumulator D in position 4-5 of the vector
	
		LDD	#&8		;load accumulator D with '0d8'
	
		STD	6,x		;store accumulator D in position 6-7 of the vector
		
		LDD	#&12		;load accumulator D with '0d12'
 		
		STD	8,x		;store accumulator D in position 8-9 of the vector
		
		LDD	#&0		;load accumulator D with '0d0'
		
		STD	10,x		;store accumulator D in position 10-11 of the vector
	
		LDD	#&36		;load accumulator D with '0d36'
	
		STD	12,x		;store accumulator D in position 12-13 of the vector
		
		LDD	#&0		;load accumulator D with '0d0'
		
		STD	14,x		;store accumulator D in position 14-15 of the vector
		
		LDD	#&9		;load accumulator D with '0d9'
		
		STD	16,x		;store accumulator D in position 16-17 of the vector

		LDD	#&22		;load accumulator D with '0d22'

		STD	18,x		;store accumulator D in position 18-19 of the vector

* =============================================================================================

loop		LDAB	pos		;load accumulator B with pos controller address

		LDX	#vector		;load index register X with vector address
		
		ABX			;increment position in vector

		LDD	0,x		;load accumulator D with vector content

* =============================================================================================

is_even		LDX	#2		;load index register X with number 2 (divisor)

		IDIV			;calculate integer division of accumulator D by X

		CPD	#0		;compare accumulator D (became remainder) with 0

		BEQ	increment	;go to loop if comparison result is equal to 0

		JMP 	continue	;go to continue section, jumping the counter increment

* =============================================================================================

increment	LDAA	count		;load accumulator A with counter address

		INCA			;increment counter

		STAA	count		;store accumulator A, saving the new counter value

* =============================================================================================

continue	LDAA	pos		;load accumulator A with pos controller address

		INCA			;increment counter, going to the first next byte
		
		INCA			;increment counter, going to the second next byte		

		STAA	pos		;store accumulator A, saving the new current position

		CMPA	#size		;compare accumulator A with vector size

		BNE	loop		;go to loop if comparison result is not equal to 0

* =============================================================================================
		
END