Re: 747 Rom Emulator / design

[rr <RRauscher@nni.com>]

Hmm, other things? Maybe mirror the ecm ram and send the
data out the serial link to the laptop?

BobR.

Steven Ciciora wrote:

> On Thu, 27 Jul 2000, rr wrote:
>
> >
> > Dual port ram is really not required. It's expensive and can be
> > tough to get. Remember that the ecm's bus cycle time is almost
> > a usec. Some 100 to 150 nsec SRAM can easily be updated
> > within a part of the cycle.
>
> But isolating the RAM from the ecm bus and from the PIC bus takes a
> bunch of 20 pin chips.  This is why I bought a Xilinx development system
> (It was delivered today; can hardly wait to get home!).
>
> >
> > Another way to look at it is: Does it matter if the ecm goes into
> > limp when your updating the ram, you can't be driving at
> > the same time your punching keys on a laptop.
> >
> > BobR.
>
> There are _other_ things I want to do, besides an eprom emulator :-)
>
> - Steven Ciciora
>
>

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