From: LEEK@QUCDN.QueensU.CA
Subject: Re: TECH: U of I Powerglove update 7-10-92
Date: Wednesday, 15 Jul 1992 13:35:33 EDT
Organization: Queen's University at Kingston



In article <1992Jul12.223708.12769@u.washington.edu>,
jlb31348@uxa.cso.uiuc.edu (Jim Brain) says:

>        Does anyone really care about A/D ports?  I ask because I could
>probably get a little more speed from either the HC11 , or another chip, if
>I did not provide that.  If you do care, What will you use them for?  Could
>I make a slow interface for you?

You can alway set up the 68HC11 A/D subsystem to do continuous
sampling of 4 channels of A/D inputs.  Whenever you need the data, you
simple go out and grap it off the 4 registers that holds the previous
conversion.  That hardly uses any CPU time at all.  There are faster
versions of HC11 chips these days.  I think the newer membrs can run
at 2X speeds.  There are also the 68HC16's too.

If you have extra code space and an extra I/O, you can have the HC11
use a different piece of code (ie one without A/D data for faster
speed) if the user pull out a jumper.

>        What about programmability?  I put it in because I was not sure we
>could get all the bugs out, so you might have to upload a new version of the
>code after you received the product.  If I can make it bug proof, will
>anyone need it?

All you have to is to use the HC11 with a large enough EEPROM and use
bootstrap mode (built-in) to program the new code from the serial
link.  The hardware complexity of this is one the order of adding a
jumper.  Leave it in.  Nothing is bug proof.  Again a different
version of code can be put in at a later date if someone figure a much
faster way of doing things.


K. C. Lee
Elec. Eng. Grad. Student