thanks to all for the replies.

i like to know how to make the follwing program an "INTERRUPT DRIVEN" one ?

Here, this program could not do anything other than just counting.(because it waits as long as TF0 is set, due to the SJMP $ instructon.

i am just a beginner in asssembly programming . so please explain in detail.






clr et0 ;pulse width generation
clr tr0
setb ea
mov a,#00h
mov r5,#00h
mov tmod,#01h
mov tl0,11h
mov th0,r7
setb et0
setb tr0
sjmp $


org 000bh


cpl a
mov p1,a

cjne a,#00h,on

;if a=0 then jump to on value
;if a=1, then jump to off value

mov tl0,11h
mov th0,r7
reti

on: mov tl0,13h ;on time low byte
mov th0,r6

reti