This discussion has been locked.
You can no longer post new replies to this discussion. If you have a question you can start a new discussion

problem regarding garbage value

Hi,

I have developed a software in c(embedded).I used c51 compiler,8051(ATmel) microprocessor.I programmed to spot billing machines(machines that generate electricity bills) with the software.It is working fine in some machines,whereas in some machines iam getting a grabage value(for TAX column).WE calculate tax.

Iam not able to identify the problem.Please give me a suggestion.what would be the problem.


thanx in advance.

Parents Reply Children
  • "Timing"

    Very possibly.

    For example:

    The 17 machines are all rather old and slow;
    they are all within the spec, but towards the slow end of all the permitted timings.
    Your unit works fine with these.

    The other 3 machines are newer and quicker;
    they are also all within the spec, but towards the fast end of all the permitted timings.
    Your unit is not quite fast enough, and so it fails with these units.

    Or, conversely:
    The 17 machines are all new and quick;
    they are all within the spec, but towards the fast end of all the permitted timings.
    Your unit works fine with these.

    The other 3 machines are older and slower;
    they are also all within the spec, but towards the slow end of all the permitted timings.
    Your unit is actually a little too quick on its timeouts, and so it fails with these units.


    The above illustrate how your unit could have a bug (in the timing), and yet work with some machines and not others.

    This doesn't prove that it is your bug - just that it could be your bug.