Re: Dynamic RAM / memory expansion

From: John (john_at_ucc.gu.uwa.edu.au)
Date: 2001-01-19 08:47:54

>Refreshing most 256k chips/simms, by the way, is exteremely simple.  All
>you have to do is flash CAS (or Ras? cant remembr) alone, and it'll
>refresh the correct row, and update the counter accordingly (one that's
>INCIDE the ram)

It's been a while, but from memory if /CAS is low on the falling edge of
/RAS, it will do an automatic refresh.  This can be 'hidden' on normal
accesses by keeping /CAS low after you've finished, then taking /RAS high,
then low, then both high.

The usual multitude of timing restrictions applies.  Consult the data sheet
if you're going to do either.

John
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