EPROM Question

[Dave McGuire]

On Sep 14, 2007, at 7:49 PM, Chris M wrote:
>  I'm not familiar with algorithmic steps in eprom
> programming. Could this roughly be likened to a
> protocol like those used in serial communications (if
> I'm correct, I'll assume they'd be much simpler).
>  On the other hand does the programming algorithm
> translate to the *timing* issues that were mentioned
> in a previous post? Or are they related to
> rise-and-fall times and that such issues.

   For EPROMs, it's a matter of setting the address/data/CS/etc lines  
and activating the programming voltage at the right times, typically  
repeating many times per location.  "Smart" or adaptive algorithms  
will pulse the location with the right bit values until they read  
back correctly, then do N number of additional cycles for a safety  
margin.

   Parallel flash chips do things very differently...you typically  
need to write a certain pattern of bytes to a certain location to  
"unlock" the device, then it can be written to.

           -Dave

-- 
Dave McGuire
Port Charlotte, FL
Farewell Ophelia, 9/22/1991 - 7/25/2007