Ashwin,

this is obviously not the complete code. The initial section is missing, and the LCD routines, at least. I know it is not absolutely vital to post them; in fact, it is better if you first try to reduce the code to the absolute minimum so that is still exhibits your problem but does not contain unnecessary parts. But, please, always post the whole code here, so that we can try to assemble it etc.

Also, you don't need to post the whole thing here in the Forum, you might set up your own 8052.com "homepage" and you have some 512kB space there to place files, then you can post only the link here.

Now, to my question. How do you know that the problem lies where you located it? What do you expect it will do and what does it do in reality?

If you want my guess, the problem lies in the comment in the following line:

ACALL KEYPAD_READY         ; this routine scans the keypad and puts the pressed button\'s value to TEMP_DIGIT

The KEYPAD_READY is NOT only a scan, it also waits until the key is released.

For me, your keypad scanning routines are a little bit messy. I'd suggest to you, first draw a flowchart of the logic of the keyboard scanning, how do you want it to work; and then try to rewrite it so it matches the flowchart.

Jan Waclawek



PS. You have an error in the keypad_reset routine; if a key would be pressed at startup, it fills up the stack