Flash swapped address line.

[Ward]

If your research the Intel ap notes on the 512 Flash chip you will find the
recomended "twisting" of the address lines to help a "noise" problem> I
think these were the frist large scale production of theses chips.

Orignialy I bugged them out from the CPU address pins. Then I wrote a small
application to un-twist them, after learing to down load and up load them,
the de-solder techneque quickly fell in to diss-use.

Ward

Ward

On Sun, 27 Jun 1999 15:16:26 -0400, Ken Kelly wrote:

> Terry,
> 	I just looked at my code. It Know it works. It will take the prom images
i got
> from the T & E chips that I removed from my PCM and convert them to a good
(%
> LT1 prom image? It swaps as I indicated. I sent you a copy of my software
to
> try.
> 
> 		Ken
> 
> TK wrote:
> > 
> > I don't think this is right. The swap involves A0. I haven't figured out
the
> > others yet.
> > 
> > 4FC7 winds up at 0FF6, so 1 is being subtracted in the address.
> > Same for 4FC8 -> 0FF7
> > Terry
> > -----Original Message-----
> > From: Ken Kelly <kenkelly at lucent.com>
> > To: gmecm at efi332.eng.ohio-state.edu <gmecm at efi332.eng.ohio-state.edu>
> > Date: Sunday, June 27, 1999 4:22 AM
> > Subject: Re: Flash swapped address line.
> > 
> > >Terry,
> > > I built a function into my editor to swap them back and forth. It can
read
> > the
> > >raw Eprom format or the standard format.
> > >
> > >I think I ended up swapping A1 and A13,  A2 and A12,  A3 and A11.
> > >
> > > Ken
> > >
> > >TK wrote:
> > >>
> > >> I've been working on a 95 LT1 ECM and it's clear the address lines to
the
> > >> flash eproms are swapped.
> > >>
> > >> Any chance you know which ones? The first 2K should be FF and there
are
> > >> groups of non-FF bytes in there.
> > >>
> > >> Any information appreciated.
> > >>
> > >> Terry Kelley
> > >





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