Hello,
I am detecting p2.0 bit for a definite time period and if it is not changed for the given time period, it restart the program again.
But the problem is that when the program is returning without using RETI it doesnt works correctly
pls give some idea to solve it.
The origional program is as under

ORG 00H
JMP MAIN
ORG 1BH
JMP DETECTION

ORG 030H
MAIN:
MOV R0,#00H
MOV TMOD,#11H
MOV TCON,#00H
MOV TH1,#0FFH
MOV TL1,#0F0H
SETB EA
SETB ET1
SETB TR1
JNB P2.0,$ ; detecting p2.0's status for the given time period and if it
;is not complemented twice timer interupt will be generated
JB P2.0,$
CLR TR1

HR: CPL P3.1
JMP MAIN

DETECTION:
CLR TR1
CLR TF1
MOV TH1,#0FFH
MOV TL1,#0F0H
INC R0
CJNE R0,#2,RETURN

JMP MAIN

RETURN:
SETB TR1
RETI
END