Parallax have kindly sent me one of their precious few new P2 EVAL boards that arrived earlier today. I forgot that Chip mentioned something a few weeks ago about mounting the few chips he had knowing that some might not work due to poor wire bonds on the leadframe side. When I got the board it came with a HyperRAM+HyperFlash module which I automatically plugged in and then I powered it up. Something wasn't right because the ROM wasn't responding on the serial terminal so I unplugged the module and powered up again and it worked. I was a little bit concerned but I have only just double checked it now and found that I had plugged the module in upside down and the two grounds of the module were shorting +5V and VIO, while the modules VIO was connected to ground. Ooops!. But plugging it back in now it seems fine. Close call!
After that initial close call I tried loading my latest TAQOZ onto the board but nothing seemed to happen. After a few hours of debugging by driving the P56 LED at various points in my code it dawned on me that the P2 was being reset by the loader after loading since I use loadp2 on Linux. So I cut the DTR-RST track that is meant to be cut and installed a 2-pin header and jumper in the off position and rely on manual reset which suits me very well indeed because this is the exact same thing I did to the original EVAL board although in its case I had to flick a 0402 cap off the pcb.
Then P2 EVAL Revb came to life and after playing with it for a while checking it out I even clocked it up to 399MHz and I have had it running for several hours now, not even warm and only using my serial coms USB for power.
It's a bit late here now but I will run through my audio/video tests tomorrow and see if I can make up a HDMI cable (really needs a module). But what I really want to do is some audio processing work which I will get onto shortly. I'm not sure what I need to do yet to get the memory module running though.
The P2 seems to die as soon as I select 400MHz but I will try some other more optimal PLL settings.
TAQOZ# fibos ---
fibo(1) = 457 cycles= 1,145ns @399MHz result = 1
fibo(6) = 777 cycles= 1,947ns @399MHz result = 8
fibo(11) = 1,097 cycles= 2,749ns @399MHz result = 89
fibo(16) = 1,417 cycles= 3,551ns @399MHz result = 987
fibo(21) = 1,737 cycles= 4,353ns @399MHz result = 10,946
fibo(26) = 2,057 cycles= 5,155ns @399MHz result = 121,393
fibo(31) = 2,377 cycles= 5,957ns @399MHz result = 1,346,269
fibo(36) = 2,697 cycles= 6,759ns @399MHz result = 14,930,352
fibo(41) = 3,017 cycles= 7,561ns @399MHz result = 165,580,141
fibo(46) = 3,337 cycles= 8,363ns @399MHz result = 1,836,311,903 ok
TAQOZ# MOUNT --- CARD: SANDISK SD SL08G REV$80 #168665696 DATE:2016/2
*** SPEEDS ***
BLOCKS.......................... 3,999kB/s @399MHz