4.3 Count the 1 into a bin number, given its decimal number

;Write a program that counts the number of bit at 1 in the binary representation of a variable of type byte

DIM EQU 8
.MODEL small
.STACK
.DATA
var DB 1
.CODE
.STARTUP
MOV AL,var
MOV CX,DIM
XOR BX,BX
ciclo:  DEC CX
        SHR AL,1  ;Coincides to the division by 2
        JC sum
        ciclo1:
        CMP AL,0
        JNZ ciclo
        JZ ex ;So when I finish to cycle, It doesn't pass through sum cycle

sum: INC BX
     JMP ciclo1
ex:
.exit
END

;My strategy was: I divide my number
;always by 2, and whenever that I have remainder, that is
;when the Carry Flag is up to 1, go in sum cycle
;and increases BX that acts as a counter, then return
;at ciclo the value 1 (it is optional) so
;I regain the code where I was remained