exxos's DFB1 trials

[exxos]

Here's the zip:

Thanks that worked. 58k unzipped.

[exxos]

Seems okay as far as I can tell..

I don't know why the vertical seems to judder but it does that on a stock setup anyway.. I know it mentioned previously but not sure if that was a bug in the program which someone was talking about the other day or my TV sux.

[Badwolf]

Seems okay as far as I can tell..

Works a lot better than mine!

Must be your pedestrian 40MHz machine.

BW

[exxos]

Must be your pedestrian 40MHz machine.

I guess I should put the 50MHz OSC back in and try that out a bit.. Obviously the FPU is out of the question without running.

EDIT:

Seems to get to the logo then locks up somehow But it may need a lesser value capacitor on the OSC or something.

[Badwolf]

Seems to get to the logo then locks up somehow But it may need a lesser value capacitor on the OSC or something.

There's a go-slow on start up (watch the second LED). Could be it runs until it tries to change up to the new OSC value.

BW

[exxos]

There's a go-slow on start up (watch the second LED). Could be it runs until it tries to change up to the new OSC value.

ah yeah.. It seems light up and then it stops dead... That is possible something is just not stable running at 50MHz.. Again we are back to anything going on there from the CPU not running at that speed (but it was tested on the ST536 at 50MHz) or something still tripping up on this board at high speeds. Again this could be related to the capacitors or something else on the firmware tripping up. Difficult to really know.

I tried 2 capacitors in series for 50pF. Still the same. Oddly removing the capacitors and it gets to memory test. But now knowing something is going on screwy internally in the PLD without the caps.. I think this is somewhat of a red herring to another problem somewhere.

We also have not looked into the actual CPU clock itself much yet either.

[exxos]

So that is even more bizarre now.. With the capacitor on the clock, the low period the CPU clock is almost non-existent

Take some images but the battery went in the camera

[Badwolf]

We also have not looked into the actual CPU clock itself much yet either.

That board passed hours of soak tests at 50MHz as was shipped. Only the FPU had issues.

I normally run Doom in a window under MiNT in 640x400 TC mode and then launch YAARTTT in the background and leave that going for an evening.

I'd be surprised if you find anything wrong with the CPU clock.

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[exxos]

IMG_0261.JPG (249.4 KiB) Viewed 1025 times

IMG_0260.JPG (245.38 KiB) Viewed 1025 times

[Badwolf]

That's not a trace, that's the oscilloscope monster's fangs!

BW