I have two tasks in my program. One is waitting char input from keyboard. the other is to check switches status.
I want to use Timer to do it

timer start
task1
if timer is overflow, go to task 2.
task2 is finished? go to timer start

I hope to use
jnb ri, $
but timer also need this jnb, timer flag, $.
How can I do this job

Thanks
Frank