Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP
Posting-Version: version B 2.10.2 (Tek) 9/28/84 based on 9/17/84; site tekigm.UUCP
Path: utzoo!decvax!tektronix!tekigm!lovedav
From: lovedav@tekigm.UUCP (Dave Hiltner)
Newsgroups: net.micro.68k
Subject: Re: seeking advice on dynamic memory controller
Message-ID: <298@tekigm.UUCP>
Date: Thu, 21-Mar-85 11:09:38 EDT
Article-I.D.: tekigm.298
Posted: Thu Mar 21 11:09:38 1985
Date-Received: Thu, 9-May-85 07:58:20 EDT
References: <421@umd5.UUCP> <1476@watcgl.UUCP>
Reply-To: lovedav@tekigm.UUCP (Dave Hiltner)
Distribution: na
Organization: Tektronix, Beaverton OR
Lines: 44
Xref: tektronix net.micro.68k:00790 
Summary: 

In article <1476@watcgl.UUCP> jchapman@watcgl.UUCP (john chapman) writes:
>> ...
>> I was considering a design using the Intel 8203 dynamic RAM controller.
>> Is this a good idea?  Are there any alternatives that I should look into?
>> -- 
>> --
>> Louis A. Mamakos WA3YMH   University of Maryland, Computer Science Center
>
> The 8203 is very easy to design with and does just about everything
> you would want; ...
> 
> John


We've recently been working on a couple of 68k implementations and have
found that Signetics has intro'd a 74LS764 DRAM controller that is (or
appears to be) VERY easy to use.  It even generates DTACK for you, though
some gating is advisable.  It does early writes, and is dual ported.  If
someone is considering the Intel 8207 I definately recommend talking to
your Signetics rep first.

The "important" data is:

Package, 40 pin

Clock rate, <50MHz

Refresh rate, x50 from Refresh Clock

Drives up to 32 RAMs direct (except WE.  Supplies gate signal, you
supply R/W and any other gating necessary (like data strobe)).

Works with 256k x 1 RAMs.

Price, about $25 in quantity.

Dtack is generated 4.5-5.5 Clocks after Request, and the cycle is
complete at that time except for precharges.

In the end, I guess I'd recommend this part, but this is not to be taken
as an endorsement by TEKTRONIX or anybody else, maybe not even me.

Hope this helps.   Dave Hiltner, Tektronix, POB 3500, MS C1-972, Vancouver
                   Wash., 98668.   (tektronix!tekigm!lovedav)