[sdiy] HMI-200 8051 ICE Ext. Clk

[Tony Kalomiris]

Peter, that makes sense. I didn't scope the clock on the target to see if
the long cabling (twisted pair) is upsetting the clock. In the Jupiter-6
case I always wondered about the two or more feet of unshielded wire
clocking the slave uC's. Which ICE are you using, I would like to look that
up myself. So this clock then would need to substituted for the targets
external clock I imagine. This is an older unit with no local pod.

Barry in the case of the HMI-200 8051 ICE it is not designed to work with
targets that don't use external clocks. Frankly I was surprised that a unit
of this calibre wouldn't take this into account. Do you remember if you
ever it in this 'external clock' configuration? I will experiment with
cable length, shielded coax, and an local oscillator, as Peter suggests.

Grant, the MMT-8 makes an excellent music 8051  development system :80C31,
32 K of battery-backed up SRAM, 32 K Code space, 2 x 16 line Hitachi LCD,
MIDI in and out, and all those buttons and leds! I used this exclusively
for years with my Scanlon eprom emulator to write and debug code. I know
this is old school. No the bits are no scrambled, at least not in the
version 1.05 and 1.08 I have. I have disassemble both and they are normal.

I want or need to go as low as 6 MHz external clocks i.e Alesis Midiverb,
(it uses double baud rate flag) as well. So a /2 divider will need to be
built as well.


Again this is the old blue monster with very slow serial port, screen
updates are painfully slow. Succeeding models have faster UARTS and
parallel and lan ports. Maybe one day I can get in there and hack a
solution, but not ready to undertake such a thing right now.

Tony K

On Wed, Oct 12, 2016 at 11:56 AM, MTG <grant at musictechnologiesgroup.com>
wrote:

> We might also have one of these old beasts at work. Or perhaps another
> brand from the same era. I will dig around. Interesting about the MMT8 as a
> dev system. I think they scrambled the LCD data lines or EPROM data lines
> on that one. Can't remember for sure. I always thought the old modems would
> make a good start. 8031, EPROM, RAM, serial port(s)...
>
> GB
>
> On 10/12/2016 8:43 AM, Barry Klein wrote:
>
>> Too long ago for me to remember but having lunch today with an engineer
>> that used it quite a bit in the early 90's(?) if he remembers I'll let
>> you know. In the meantime I found this about another emulator:
>>
>> It is dissuaded to use a crystal in the target as a clock source during
>> the emulation. It is recommended that the oscillator be used instead.
>> Normally, a crystal and two capacitors are connected to the CPU's clock
>> inputs in the target application as stated in the CPU datasheets. A
>> length of clock paths is critical and must be taken into consideration
>> when designing the target. During the emulation, the distance between
>> the crystal in the target and the CPU (on the POD) is furthermore
>> increased; therefore the impedance may change in a manner that the
>> crystal doesn't oscillate anymore. In such case, a standalone crystal
>> circuit, oscillating already without the CPU must be built or an
>> oscillator must be used.
>>
>>
>> Barry
>>
>> On Oct 11, 2016, at 8:52 PM, Tony K <weplar at gmail.com
>> <mailto:weplar at gmail.com>> wrote:
>>
>> Hi there folks, time for me to ask for help this time.
>>>
>>> I recently revisited my old 8051 music development projects and have
>>> never tried using the targets external clock but used the ICE's
>>> internal 16 MHz clock. This has been okay for things up to now but for
>>> s/w timing loops and such of course this is unacceptable. Basically
>>> the problem is the emulator software - and I have the Huntsville DOS ,
>>> 16 and 32 bit software running on a slow serial port (38400 max) -
>>> crashes or times out when I set ext. clk in the configuration page.
>>> Always works with it's internal clock.
>>>
>>> The test target was the Jupiter-6's own 12 Mhz oscillator which is
>>> 'double buffered' before going to the slave voice micros. Another
>>> question I had was how do you get these emulators to work with targets
>>> that use crystals or ceramic resonators and the internal 8051
>>> oscillator ? It seems that would be obvious oversight. The
>>> documentation is of no help.. well maybe a little.
>>>
>>> My dev system consists if an MMT-8, an Eprom Emulator and this ICE I
>>> acquired recently and had tried it with the MMT-8.
>>>
>>> Sorry if any of this is confusing.
>>> This is am older Huntsville Microsystems 8051 ICE, very powerful but
>>> slow (38400 baud) !
>>>
>>> Barry if you can chime in here that would be great, thanks everyone.
>>>
>>> TK
>>> _______________________________________________
>>> Synth-diy mailing list
>>> Synth-diy at dropmix.xs4all.nl <mailto:Synth-diy at dropmix.xs4all.nl>
>>> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
>>>
>>
>>
>> _______________________________________________
>> Synth-diy mailing list
>> Synth-diy at dropmix.xs4all.nl
>> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
>>
>> _______________________________________________
> Synth-diy mailing list
> Synth-diy at dropmix.xs4all.nl
> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://synth-diy.org/pipermail/synth-diy/attachments/20161012/0187139c/attachment.htm>