I swapped my H5 for a H4 and made no odds.
I added in a cache off into TOS for the rev5 and it then passed ROM and TTram check.. But CDIS doesn't seem to help at all now. It's like the fault got worse for no reason like the later rev board. I'm just totally baffled.
The ROM copy errors in TOS startup seem fixed. It seems to show the first word coopied then not the second. BUT, if I can get to desktop and run my ROM verification program, it then verifies fine.. So the copy worked?!
There could be some odd cache issues going on. But you would think during TTram test it wouldn't fail on the whole TTram range.. BUT it will get to desktop and pass every YAARTTT test. It just makes no sense at all.
As things are going from bad to worse, I can only think the constant board swapping is to blame. But this then makes me wonder if the PCBs themselves are just bad. Like bad vias which are breaking more and more as time goes on and its just giving me all these odd faults.
I've half been wondering about trying a different PCB manufacture and maybe even using 2mm thick PCB.. But it wouldn't be conclusive without building up 10 boards to rule out tolerances. It be a rather expensive experiment
Only thing I could try is continuity check the whole board. Most internal layers are power planes. So worth a shot. Beyond that I'm out of ideas.
The 536 code isn't even that complicated and I've ran barebones firmware which half the time isn't even stable at 8MHz. But even so, it's like the same weird problems since day 1. It seems the same story.. Everything works fine for ages. Then things just go downhill for no reason.
I mean literally, board works fine for weeks, then just goes nuts never to work again. Same story with the rev5 was working fine then just went nuts. I've resoldered the board, changed the ram, CPU, socket, PLD, regulator.. Still refuses to behave. Plus with my later board just stopped working out of the blue.. What else is left other than the PCB itself failing?
