From: dwilliam@jabba.ess.harris.com (Dave Williams)
Subject: Re: Miniboard or Motorola eval board?
Organization: Harris Corporation - ISD
Date: Thu, 5 Nov 1992 21:53:13 GMT

In <1992Nov4.133417.8689@reed.edu> reeder@reed.edu (P. Douglas Reeder) writes:

>In article <1992Nov3.135508.2766@news.media.mit.edu> fredm@media.mit.edu (Fred G Martin) writes:
>:Reasons you would not choose the Mini Board:
>:
>:* There is no prototyping area on the MB.  I believe the EVB has some

>There are no protoyping areas on the EVB.  (Unless they've changed the
>design since I got mine.)  Note that the EVB is intended to simulate 
>an HC11 with replaceable ROM, to help one design HC11-using devices.
>It thus is not really designed to be used in a non-prototype system.

   Just a note here - the EVB board is an earlier, more feature-laden
board as compared to the later EVBU board that Mot. will sell you these
days for $68.11.  (I have one of both.)  The EVB board is intended to
act like an ICE (in circuit emulator) for a 6811 operating in single-chip
mode.  It includes a PRU (port replacement unit) that gives you back 
the three (two?) ports used up for the bus interface.  The board has
a ROM for the buffalo monitor and two ROM/RAM sockets.  (Mine came
with an 8K SRAM in one of the sockets, and nothing in the other.)  There
are two serial ports, one from a UART, and one from the 6811 itself.
(The 6811 serial port is fixed at 9600 baud under buffalo, the other
port is jumper-selectable for baud rate.)

   The EVBU (EVBU stands for EValuation Board, University style, by the
way) is a much less complex board.  It does not include any RAM
or ROM (other than what is in the 6811 itself), or a UART.  It does
include a prototype area, however, where you can build custom hardware.
Mot. supplies a program for PCs called PCBug11 that operates via the
bootstrap mode of the 6811.  What happens, is you power everything up,
and PCBug11 loads a "talker" program into the 6811.  This program is
used to modify the 6811's internal registers and memory under control
of the PC.  What you have here is a replacement for the buffalo monitor.
You start up PCBug11, and download your program into the internal
memory, then use the PC as a debug monitor.  Simple, no?  I was a TA
at Clemson University for a whole class of students using EVBU's to
build various robot stuff.  On the whole, I'd say it worked pretty 
well, if you got a working board.  (It seems like EVBUs either work
fine, or or dead out of the box.  Maybe Clemson hit a bad run of 
boards or something.)
   
>Functionally, the HC11 is always in single-chip operating mode, so
>hardware not part of the EVB cannot be in the memory map.  This means 
>you are forever limited to the two 8K blocks of RAM (though you could
>replace the 8K ROM with one of your own).

   Hummm.  I wouldn't say that - There's quite a few holes in the
EVB memory map where you could put all sorts of nifty stuff.

>A furthur point is that the EVB monitor takes up 182 bytes of the 
>zero-page RAM.

   If you use the PCBug11 software to drive the EVB board, you get 
away from that.  (Of course, the PCBug11 software still chews up
some memory, but you can use EEPROM memory for that)

   I've never had a problem with the buffalo monitor chewing up 
the zero-page RAM.  Especially with that nice 8K RAM sitting out
there.  My normal routine is to burn my programs into an 8K EEPROM
plugged into the 2nd RAM socket, and run them out of that critter.

   Hummm.  This "note" turns out to have been longer than I intended.
Oh well.

  Dave Williams                                     | I'm lucky if I can
    dwilliam@jabba.ess.harris.com                   | even spell opinion,
      "Huh?  What?  Could you repeat the question?" | much less have them.


-- 
  Dave Williams                                     | I'm lucky if I can
    dwilliam@jabba.ess.harris.com                   | even spell opinion,
      "Huh?  What?  Could you repeat the question?" | much less have them.
Newsgroups: comp.robotics,rec.video,rec.video.production,rec.photo