I've been so busy struggling with the ROM code that I haven't made a board for these, yet. I'll make a board that will plug into the Prop123, so that these chips can be exercised as if they were part of the core logic.
Looking good, some partial P2 silicon is always good. Which analog functions are you testing?
Everything. All elements of the pad frame are in there. So, there are two I/O pins (4 fuses in each), the clock pads (RCFAST/RCSLOW/XTAL/PLL), and the RESn and TESn pads.
If you want this board done quickly, feel free to ask Michael or David to just get it done for you, Chip. We're all interested in the results of your first look at this test chip.
Looks like it's .5mm. Plenty of breakout boards for that footprint.
I had a quick look but didn't find much in square 128 pin 0.5mm. There were rectangular 128 pin qfp package breakouts (RE470), however I suspect the 144 pin breakouts would work as these are also designed for 20x20mm
Can you do grayscale VGA with this?
Seems like maybe it could...
It certainly should be possible to confirm the DAC Drive, and Slew rates on changes (bandwidth), and create some test patterns, and test things like Sync-On-Green.
Limited Colour VGA and Limited Colour Component Video should be possible with 2 DACs.
The final change-rate will be dictated by how quickly the test interface can update the DACS, so it might not manage full VGA pixel-change-rates.
I think I remember someone here saying there's some trick to send VGA with only two I/O, by XORing the hsync and vsync together or something like that.
Could you instead just use two chips to get 4 I/O?
Comments
And here is the pinout, as if it had gone into the originally intended 80-pin package:
Everything. All elements of the pad frame are in there. So, there are two I/O pins (4 fuses in each), the clock pads (RCFAST/RCSLOW/XTAL/PLL), and the RESn and TESn pads.
Good luck with the testing.
Starts biting finger nails, nervously waiting for test results...
Fingers and toes crossed that all functions as expected!!!
You might be able to buy a PLCC128 breakout board off the shelf to start some testing while you layout and wait for your own pcbs.
BTW what is the pitch of these chips?
Looks like it's .5mm. Plenty of breakout boards for that footprint.
Ken Gracey
I had a quick look but didn't find much in square 128 pin 0.5mm. There were rectangular 128 pin qfp package breakouts (RE470), however I suspect the 144 pin breakouts would work as these are also designed for 20x20mm
http://uk.rs-online.com/web/p/surface-mount-smt-to-through-hole-adapter-boards/3675219/
Hey, will we be able to test DAC input?
It has two instances of the I/O pad. So, we've got both DAC and ADC.
Which foundry did you use? I expected to be ON Semi, and on a different package as well. Also, are those 180nm testchips?
Kind regards, Samuel Lourenço
Yes, OnSemi made these and they use the ONC18 process.
Not quite. This is only the ring (analog, smart pins, etc), no cogs or hub memory.
Seems like maybe it could...
Limited Colour VGA and Limited Colour Component Video should be possible with 2 DACs.
The final change-rate will be dictated by how quickly the test interface can update the DACS, so it might not manage full VGA pixel-change-rates.
Could you instead just use two chips to get 4 I/O?
Strictly, yes, but whatever is driving the test chip, I figured could easily manage H,V Syncs.
You could just duplicate/divert the signals to the P2 test silicon and see how it looks, side by side.