Path: utzoo!mnetor!uunet!husc6!cmcl2!brl-adm!umd5!purdue!i.cc.purdue.edu!j.cc.purdue.edu!pur-ee!uiucdcs!uxc.cso.uiuc.edu!ccvaxa!aglew
From: aglew@ccvaxa.UUCP
Newsgroups: comp.arch
Subject: Re: Cycle stretching
Message-ID: <28200107@ccvaxa>
Date: 21 Feb 88 17:41:00 GMT
References: <844@daisy.UUCP>
Lines: 21
Nf-ID: #R:daisy.UUCP:844:ccvaxa:28200107:000:1051
Nf-From: ccvaxa.UUCP!aglew    Feb 21 11:41:00 1988


..> Variable clock rates

(1) There's a company that sells a box for the VAX (I think 750, but not
    sure) that varies the clock rate according to processor activity.
    They say that they can get an extra 15% out of your old tired VAX.

    Not sure of details - just crossed this in some DEC magazine.

(2) I've always liked the idea of self timed circuitry (note that this
    is an order of scale different from varying clock rates), but have
    a question that someone with more experience with self timed techniques
    can answer.

    Am I correct in saying that a trivial way of obtaining a self timed
    circuit is to take a "normal" circuit, say an adder, and put a timing
    circuit beside it that will produce a pulse when the adder is finished?
    And that there are "transformations" that will more closely intertwine
    the timing circuit with the function, so that they share gates?
    Doesn't this require extremely accurate parametrization of the device's
    performance, more than is required for non-self-timed systems?