Program to count from 0-9 in 8051

here:mov a,#0h ;move 0 to a

up:mov p0,a ;move data from a to port0

acall delay ;call delay routine

add a,#01 ;increment a

cjne a,#010,up ;compare a with 10, if not equal, jump to location up

sjmp here ;jump to location here

;delay routine

delay:mov r1,#0ffh ;move 0ffh to r1

l3:mov r2,#0ffh ;move 0ffh to r2

l2:mov r3,#0ffh ;move 0ffh to r3

l1:djnz r1,l1 ;decrement r1, repeat till r1=0

djnz r3,l2 ;decrement r3,repeat l2 till r3=0

djnz r2,l3 ;decrement r2, repeat l3 till r2=0

ret ;return

end