new instruction : Call and push,pop

org 100h

mov al,01h

mov ah,01h

mov dl,02h

mov cx,0000h

mov bl,al

call square

add cx,bx

mov bl,ah

call square

add cx,bx

mov bl,dl

call square

add cx,bx

         

 square: 

push ax

mov al,bl

mul bl

mov bx,ax

pop ax

ret 

hlt

note : CX must be = 6 in this example