EPROM Emulator Proposal

[Squash]

But if dpram is battery backed, there should be no
need for a weird circuit on power-up, right?  It would
act just like an eeprom?

Andy

--- thergen at svn.net wrote:
> I think it's a good proposal.  I'd like to suggest
> that a pushbutton
> switch be part of the design that can be used to
> reload the default dpram
> bank from the eprom (assuming it's present) so that
> you can recover from a
> corrupted ram image without using a laptop computer.
>  Power-up/power-down
> need special attention (as you already know) to
> avoid corrupting the ram. 
> Maxim (www.maxim-ic.com) and others make parts with
> voltage supervisors
> specifically for memory protection (let me know if
> you want specifics). 
>  
> Tom
>  
> On Wed, 7 Apr 1999, Ludis Langens wrote:
>  
> > The EPROM emulator debate on this list seems to be
> going in circles.
> > Either people have short memories, or there are a
> lot of new members who
> > missed the discussion and decisions made in the
> first few weeks of
> > gmecm.  Either way, please read through the
> archives.
> >
> > Anyway, here is an emulator proposal based on the
> prior discussion.  I 
> > did some ruthless cutting of features and
> expandability (indicated with
> > a *).  I propose the use of a single dual-port
> SRAM (from Cypress or  
> > IDT) and a 40/44 pin PIC microcontroller to load
> this RAM.  A battery 
> > back up will keep the SRAM alive.  This allows an
> ECM to boot from the
> > DPRAM immediately upon power-up.  The whole
> emulator circuit board  
> > should be small enough to fit inside a
> '165/'727/'730/'749/'808 ECM.
> ....
> 
> 
> 
> 

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