NetNews Usenet Archive 1992 #18/NN_1992_18.iso/spool/comp/sys/m68k/1025

Text File | 1992-08-12 | 2.7 KB | 62 lines

Newsgroups: comp.sys.m68k
Path: sparky!uunet!mnemosyne.cs.du.edu!nyx!jjsmith
From: [e-mail] (Jonathan J. Smith)
Subject: Re: 020 vs 030
Message-ID: <[e-mail]>
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Date: Thu, 13 Aug 92 01:22:27 GMT
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In article <[e-mail]> [e-mail] (Floyd Goodrich) writes:
>[e-mail] (Andrew L. Hansford) writes:
>>
>>Another group is having a discussion on whether the 020 or 030 should
>>be the minimum processor used in new systems.  So I have a few
>>questions that I would like to post to a place of finding a more
>>accurate answer.
>>
>>First assume that MU is not needed by the OS so an EC030 could
>>probably be used. (Several accelerators do this)
>>
>>Given the same clock speed, the EC030 would be faster than the 020 due
>>to the data cache, and burst cycles (if the memory supports burst). Correct?
>
>Correct.  The 68030 supports burst mode (for 32-bit accesses) and has a
>256kbyte data cache.  The cache really boosts performance on loops of <256kb.
^^^^^^^^^^
it has a 256Kbyte data cache????? woah, hold on, unless Im way out in the blue yonder I was under the impression it was a great deal smaller!
(just checking, don't have a data book handy)... 256Kbytes, seems a tad on the large side though.

>Don't forget that the STERM pin on the 68030/EC030 bus interface allows you
>to terminate a bus cycle from a 32-bit memory bank in 2 clocks instead of 3
>as the 68020 requires. At the same frequency, based on dhrystones, you get:
>    020/EC030 = 0.75 in terms of performance.
>
>>Does the EC030 have any other advantaged over the 020?
>
>It's offered in clock speeds up to 50MHz instead of just up to 33MHz.  The
>package types are different, too.  Some of the bus specs are better on the 030.
>
>>IS the EC030 pin compatible with the 030 so if you needed a PMMU later
>>you could just pop a 030 in place of the EC030.  Does the EC030 have a
>>the coprocessor interface for an 882?
>
>It's pin compatible with the 030.  The EC030 retains the coprocessor interface.
>
>>What is the current $$/chip in lots of 10,000 for the 030,EC030, and 020?
>
>Call your local Motorola Sales Office.  The number in Boston is 617 932-9700
>or in Berlin, MA is 508 481-8100.  They can help you get data books, too.
>
>---
>Floyd Goodrich
>[e-mail]
>