"Eric Smith" <eric@[EMAIL PROTECTED]
> wrote in message
news:m3wsqfq0s9.fsf@[EMAIL PROTECTED]
> robb wrote:
> > - both (OE) and (CE) work as surogate latch but which is
better
> > choice ?
>
> Impossible to say without knowing the relative timing. Use a
dual-trace
> scope, trigger on OE, and look at address lines (one at a time)
on other
> trace. Make sure there seems to be enough setup time from
address valid
> to the edge of OE. In other words, the scope trace for the
address line
> shouldn't show any transitions for perhaps 20 ns before the
edge of OE.
> (Look up the required address setup time in the data sheet.)
>
> Then try the same experiment for CE.
>
> If they both show sufficient set up time, it doesn't matter,
but I'd
> choose the one that shows more.
hello Eric,
Thanks for reply,
OE shows the most delay before falling edge *BUT* that fall
occurs way ou ther about halfway accross/between the
Address/Data transitions which are maybe 150 ns wide.
CE drops about a fraction after the Address transition.
I will double check that to make sure i am being accurate but
that is my memory at the moment.
thanksfor help, ill double check,
robb
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