> >>TT_Man wrote:
>
> >>>Anyone using this part experiencing problems? we have used them for 4
> >>>years
> >>>or so. Date codes up to 0705 work ok, 0814 misbehaves....same chip, same
> >>>software, 0814 doesn't execute properly...
>
> >>Have you contacted the manufacturer ?
>
> >>Graham
>
> > Yes, that was my first port of call, with full details, source code etc.and
> > an indication of the approximate area of failure, within 10 lines of
> > code......
>
> *Within* 10 lines of code? Not more specific? Probably "C" code...
I think two causes are most likely:
(1) Something isn't being initialized. The memory locations of an 8051 are not forced reset at power on. They can have any value in them but a given chip will tend to either have highs or lows.
(2) A timing of interrupt issue. If the interrupt code messes with something that the non-interrupt code uses, the results can depend on the exact timing of interrupts. Which instruction an interrupt happens on can be effected by where the chip's 0/1 boundary is on the input lines.