Killed CPLD - IDE Interface

[GadgetUK164]

Just thought I would share this (someone else might have seen this before or be able to confirm my thought on which CPLD):-

Last night I connected up a cheap chinese SD to IDE adapter (possibly wrong away around - it was dark at the time). I found it wasn't working, so swapped back to CF card and now that doesnt work lol. Confirmed the card and adapter works, cable 100% the correct way around, so I must have blown an IO pin or two on one of the CPLDs.

I am guessing its going to be the smaller IC that handles some of the IDE signals (from a quick look at the schematics), since I can get the card to boot from Floppy (once it realises there's no HDD) - and RAM tests out OK too. If the CF is connected it just hangs forever, which leads me to speculate its perhaps waiting for a repsonse on a particular pin there.

I've ordered a spare of each CPLD.

[terriblefire]

Its very odd that this could kill the CPLD because you basically short everything to ground by doing this.

Things to check...

1. What does the 3.3v rail look like?
2. Can you still see the CPLDs on the JTAG chains?
3. Can you program the CPLDs (try a few times)
4. Does it boot diagrom?

[8 Bit Dreams]

Unfortunately there was such problem with early versions of the card, where pin stripes are used..
Pin1 IS MARKED ON THE WRONG SIDE!
as soon i have realised this - have reported issue to Stephen and it was corrected, i also started to use proper 44 headers instead of pins to avoid such situation in future..

Plugging CF to IDE adapter wrong way around doesn't brakes anything, however SD to IDE is more complex, so in theory this may happen..
I think IDE code in RAM cpld, (i may be wrong )

[GadgetUK164]

Unfortunately there was such problem with early versions of the card, where pin stripes are used..
Pin1 IS MARKED ON THE WRONG SIDE!
as soon i have realised this - have reported issue to Stephen and it was corrected, i also started to use proper 44 headers instead of pins to avoid such situation in future..

Plugging CF to IDE adapter wrong way around doesn't brakes anything, however SD to IDE is more complex, so in theory this may happen..
I think IDE code in RAM cpld, (i may be wrong )

Thanks! Yes, it's definitely a faulty CPLD. Looking at schematics the control signals for IDE look to come from the smaller CPLD. That's the one I am going to swap first as I suspect that's where one of the pins is dead.

[terriblefire]

Unfortunately there was such problem with early versions of the card, where pin stripes are used..
Pin1 IS MARKED ON THE WRONG SIDE!
as soon i have realised this - have reported issue to Stephen and it was corrected, i also started to use proper 44 headers instead of pins to avoid such situation in future..

Plugging CF to IDE adapter wrong way around doesn't brakes anything, however SD to IDE is more complex, so in theory this may happen..
I think IDE code in RAM cpld, (i may be wrong )

Thanks! Yes, it's definitely a faulty CPLD. Looking at schematics the control signals for IDE look to come from the smaller CPLD. That's the one I am going to swap first as I suspect that's where one of the pins is dead.

It’s not that simple. Both CPLDs generate the IDE interface between them. Can you run through my checklist before desoldering

[GadgetUK164]

Yeah, I saw that, but I was speculating based on the CF connection being wrong way around, and I see grounds going to some of the control signals that come from the smaller CPLD - that was my thinking.

Anyway, the good news is its working again! Fitted that CPLD, programmed it up and it works!!! Yay!! I am so relieved!

You should see the size of the box farnell used to ship me 2 CPLD chips!!! Think of the size of full length amiga 2000 accelerator card - imagine it super well packed with bubble wrap around it. That's the size of the box that turned up. 2 foil sealed trays that probably accommodate 50 ish ICs. 1 tray for the smaller CPLD, 1 tray for the larger one. Crazy lol! At first I thought they had made a mistake and sent me 2 trays of the ICs lol.

EDIT: Sorry I missed your checklist there, but I had done all that stuff at the start:-
1. What does the 3.3v rail look like? Normal
2. Can you still see the CPLDs on the JTAG chains? Yes - reprog'd them just to be sure
3. Can you program the CPLDs (try a few times) ^
4. Does it boot diagrom? Yes - diagrom normal, just the fact it would hang with a none boot (not even polling FDD) when CF was inserted. Minus CF it would after 10 secs or so fall back to FDD and boot OK.

[8 Bit Dreams]

Thanks! Yes, it's definitely a faulty CPLD. Looking at schematics the control signals for IDE look to come from the smaller CPLD. That's the one I am going to swap first as I suspect that's where one of the pins is dead.

I do understand Your frustration Chris, im feeling guilty for that what happened.. Have fried hard drive same way back in the days.. Unfortunately this is the standard situation on 44 Pin connector, this can not happen on 40 Pin connector since power pins are organised differently. Also 40pin CF to IDE adaprors had never caused issues unlike 44 pin ones.. This was the reason why ive asked Stephen to go back to 40 Pin connector..

Generally all my recomendations as a beta tester are based on my own experience, i don't ask for something I want, the only thing i'd like to achieve - is a rock solid hard breakable hardware..

Really hope You'll be able to figure out what's going on there, Chris.
Will also be glad to take a look on Your card if You can't let it work..
With kind regards,

- 8 Bit Dreams

[alenppc]

All you have to do is pay attention on how you plug the 44-pin. A600 and A1200 owners have known this for decades. Going to 40 pin is a terrible idea, since then you have to worry about finding power on the 500, getting extra connectors... etc.

Having said that I've plugged CF cards backwards on TF hardware countless times, and unlike the 600/1200 nothing happened, the card simply wouldn't start.

[terriblefire]

Going to 40 pin is a terrible idea, since then you have to worry about finding power on the 500, getting extra connectors... etc.

Completely agree. 40 pin IDE sucks. Just use an adapter...

[8 Bit Dreams]

All you have to do is pay attention on how you plug the 44-pin. A600 and A1200 owners have known this for decades. Going to 40 pin is a terrible idea, since then you have to worry about finding power on the 500, getting extra connectors... etc.

Having said that I've plugged CF cards backwards on TF hardware countless times, and unlike the 600/1200 nothing happened, the card simply wouldn't start.

This happens ONLY if pin 20 is not powered. If it's routed correctly - you don't need extra power, works same as 44 pin.
Yes, you are right, plugging CF to IDE doesn't harm like it does to hard drive. According to GadgetUK experience - wrongly plugged SD to IDE kills cpld. these are expensive if we talk about 95144's & 95288's
We are in need to switch to SD to IDE adapters since we are unable to use standard chinese CF to IDE Adapters - muFASTROM option simply doesn't work on them...