Intro to Microprocessors

From: Richard Erlacher <edick_at_idcomm.com>
Date: Thu Jul 19 12:41:51 2001

Yes, I've got one of those as well. With a little effort, BTW, you can adapt
the 60-pin expansion connector to a 52-pin header or other adapter and fit that
in to a target PGA socket on your target board, thereby giving you in-circuit
operation capabilities in spite of the fact that the 68HC11 is operated in
expanded multiplexed mode on the EVBU.

The 6801L1 is essentially the same sort of thing with less in the way of
resources, but much easier to use because it's a single chip. Th 68HC25 will
allow you to expand it into a similar system, yet give you back the use of the
ports lost in briniging out the data bus and address bus on what would otherwise
have been I/O ports.

The LILBUG is not as sophisticated as the BUFFALO monitor that's on the EVBU,
but it has the debug, line-by-line assembler, etc. functions.

There are numerous boards of this sort for a variety of microcontrollers. They
seldom address the issues associated with microprocessors, however, since
they're normally used to host single-chip mircontontrollers, e.g. 68HC05C8,
87C15x, etc. which are essentially single-chip microcomputers with all their
resources INSIDE the chip, where you can't do much to use the internal busses,
etc. Few of them actually allow you to bring out the address and data bus and
the associated control signals.

I'm constrained by NDA from explaining in detail, but, if you spend a little
time with a logic analyzer and certain MCU's from a very large MCU manufacturer,
perhaps the only one that uses the term MCU, you might learn a little about how
this can be done in spite of what the mfg prefers.

Dick
----- Original Message -----
From: "Eric Dittman" <dittman_at_dittman.net>
To: <classiccmp_at_classiccmp.org>
Sent: Thursday, July 19, 2001 12:34 AM
Subject: Re: Intro to Microprocessors


> > Yes, it'd be great to put together a learning system that way, IF the person
> > had the skill and determination to pull it off. This very scenario is why I
> > suggested (back on Sunday I think) that a good way to go would be to pick up
> > a 68HC11 Evaluation Board (EVBU or EVM). My EVBU (which is currently built
> > into a little robot) already HAS:
> > - serial port
> > - monitor & assembler/disassembler program (Buffalo)
> > - 1k EEPROM
> > - wire wrap area
> > - real-time clock
> > - assembler & download software
> > - five ports:
> > A - pulse counters or general I/O
> > B - parallel output or address selection if using ext. RAM/ROM
> > C - parallel I/O or address/data port if using ext. RAM/ROM
> > D - two comm ports or general I/O
> > E - eight analog inputs or general inputs
>
> But if you have everything already done for you do you learn the
> basics?
> --
> Eric Dittman
> dittman_at_dittman.net
>
>
Received on Thu Jul 19 2001 - 12:41:51 BST