Re: MISC-d Digest V99 #44

[theFox@xxxxxxxxxxxxxxxxxxx (Jeff Fox)]

>>I did not realize that the counter resolution was from an analog integrator.
>
>Jeff never states this explicitly. At current state of the art there is no way 
>to make a 75 MHz f/f clock at 2 GHZ. No amount of magic dust will make it so.
>
>That leaves analog.

The echo timer web page details the fact that there are in fact digital
counters running at 10gigahertz inside.  The echo timer is a digital circuit
counting at ten gigahertz.  The analog I/O coprocessor has two ramp
encoders that count through 256 digital steps in each analog sample.  At
40 msps that means that counter is also running at ten gig. 

Under the hood each instruction executes in 2ns.  Each instruction takes
about twelve steps.  So if you break the chip up into large function 
units they execute in less than .2ns.  Small circuits like counters can
run in .1ns steps.   OKAD simulates at 15ps intervals.

The literature at MOSIS states that .8u is fast enough for a 75mhz
flip flop.  It is truely remarkable that Chuck is building 10ghz
counters in this technology.  I told him not to talk about it because
first of all people just wouldn't believe it and I worried that
he would just get press for another quirky keyboard rather than
the electronic circuit to drive it.

Jeff Fox

 
Jeff Fox           
UltraTechnology