[sdiy] RAS/CAS timing

[René Schmitz]

Hi all,

Rainer Buchty wrote:
> Now that we have DRAM you need to periodically refresh the content which
> can be done in many ways:
> 
> (1) If you cyclically read all the contents within the desired time, no
> separate refresh is needed.

The requirement is only that you need to adress all the rows within the 
refresh time (some few ms). Fast page mode RAM (which this most likely 
is) refreshes all columns of the row once that row is adressed.

Look at my homepage under "Delay", there are two assembler programs, 
that show how it can be done. (But this doesn't make use of the page 
mode feature.)

Cheers,
  René

-- 
uzs159 at uni-bonn.de
http://www.uni-bonn.de/~uzs159