Another Home-Brew - Z180

General "chat", not necessarily MTX related
Bill B
Posts: 258
Joined: 26 Jan 2014 16:31

Re: Another Home-Brew - Z180

Post by Bill B »

Martin,

On less dense boards I have done that. However you have to bend the wire over to stop it just falling through the hole and the bent over bit adds to the problem of bridging adjacent tracks. That is what failed my 31st Dec attempt.

I have been trying to think of a way of evenly spreading the end of a piece of wire to create a nail head. But anything practical to make is liable to be too slow.
Bill B
Posts: 258
Joined: 26 Jan 2014 16:31

Re: Another Home-Brew - Z180

Post by Bill B »

I have surveyed the PCB with a multimeter. I found a few shorts, that I was able to correct.

Once I was happy with the board, I installed power leads and the CPLD. Connected power supply and programmer. I am using this programmer. Attempted to program the device:

Failed. JTAG error. No device detected :(

Rechecked the board with multimeter. All connections seem to be through and in the right place. Tried a second CPLD, same result :(

This is the first time I have tried to use this programmer. However Quartus seems happy with it, and the lights on the programmer appear to do what I would expect.

I think I am going to have to make some adaptor PCBs, so I can plug both the CPLD and the programmer into some breadboard.
Martin A
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Joined: 09 Nov 2013 21:03

Re: Another Home-Brew - Z180

Post by Martin A »

I had issues in the past with my "USB blaster" (it's a clone) failing to program that were basically down to the cheap USB lead that came with it not fitting properly. Once I switched to a higher quality lead the problems went away.
Bill B
Posts: 258
Joined: 26 Jan 2014 16:31

Re: Another Home-Brew - Z180

Post by Bill B »

Martin,

Thanks for the suggestion. It may be that, but I don't think so. The lead seems to be good quality and a good fit. Also there is activity on the programmer LED when attempting to program.

Experimentation is required.
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Dave
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Re: Another Home-Brew - Z180

Post by Dave »

Bill,

are you sure of the CPLDs? Some of the ones that I got from Lez had the JTAG ports locked out, if that is the problem, there is no way to reset them without an Altera Master Programmer - which are unobtanium these days.

If you are using Quartus, what is the error code/message?

regards
Dave
Bill B
Posts: 258
Joined: 26 Jan 2014 16:31

Re: Another Home-Brew - Z180

Post by Bill B »

Dave,

That issue had occurred to me, and is a possibility.

I am not sure there was an error message, other than "Failed", when attempting to program.

When I did the JTAG test, I got the "No device found" message.

I don't remember exact messages, and don't have the system in front of me at the moment.
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Dave
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Re: Another Home-Brew - Z180

Post by Dave »

Bill,

I can send you a known working 7128S if you like, that would eliminate a locked out jtag port problem

Regards
Dave
Bill B
Posts: 258
Joined: 26 Jan 2014 16:31

Re: Another Home-Brew - Z180

Post by Bill B »

Dave,

Many thanks for the offer. However I am using the smaller 7032S in my design. I have five of these chips from Lez, so hopefully at least a couple should be usable, even assuming that this is the problem. If not I will have to buy some more.

I have also been wondering how the master programmer resets the chip. Two possibilities occur to me:
  • The chip has multiple power pins. Perhaps one of these is not only power, but if taken to the opposite state acts as a "program enable".
  • Applying a higher than 5v "programming voltage" to one or more pins, as per EPROMs.
I do wish manufacturers would publish full information. It can't really be to protect against competition, who will have the tools to reverse engineer the chips. Presumably at least some of the details are published in patents.

If the chips are locked, then I don't have anything to loose doing some experiments to see what I can discover.
Martin A
Posts: 464
Joined: 09 Nov 2013 21:03

Re: Another Home-Brew - Z180

Post by Martin A »

I don't know if this is any help for testing:

https://hackaday.com/2015/10/28/program ... ore-174019

Bill Herd (of Commodore fame) put together a CPLD breadboard module for the 44 pin Max.

It could be that the master programmer also does something with voltage levels to identify itself ?? Like with an EPROM and some GALS where 1 pin has to be raised to 12v.
Bill B
Posts: 258
Joined: 26 Jan 2014 16:31

Re: Another Home-Brew - Z180

Post by Bill B »

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My boards for testing 7032 CPLD and USB Blaster on a breadboard. Now need to investigate whether I can program any of the chips.

One advantage of having made these is that I can also test the logic of the programmed CPLD independent of the main circuit.

Making these has convinced me that I was right not to use this construction method for the end circuit. I know that Martin makes many boards this way, but I can only admire his skill and patience. Not for me.
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