Counter20  equ 70h

 org 00h
 sjmp start
 org 03h
ljmp isr0
org 13h
ljmp isr1
org 0bh
ljmp tmr0
ORG     80H
 start:
 
 setb p3.2
poll:
jb p3.2,poll
 bouncing: jnb p3.2, bouncing
     setb it0
	setb ex0
main:
clr p3.7
 mov counter20,#40



	setb EA
 lcall n_delay