Quote from: ecliptic on May 02, 2013, 05:57:12 PM

Do the Avalon chips have the ability to adjust clock frequency / core voltage / etc?

I may make a fork(does that make sense for hardware?) of the board that adds the ability to do that.

It wouldn't be needed for a standard board but it'd be interesting to add

* Thermal sensors near each ASIC or heatsink that feed back over USB.
* Ability to adjust core voltage (probably by hand)
* Ability to adjust frequency (maybe digitally with a DDS, - really need the Avalon design docs to figure the best way to do this)

Edit : We will need to make sure the decoupling and board step down regulator is capable of driving 16 chips. it looks like the standard avalon board only runs 10 chips per VRM. Just really need the documentation from Avalon

Sure, you can fork away (once I put the files up). One primary reason I switched over to Kicad was that it's open source and anyone can grab it and work on their own version. I would have stuck with Eagle for 2 layers as it's more well known. Kicad has it's oddities though and a number of things I've already ran into that I can't figure what they were thinking.

I think you could easily adjust the core voltage with some sort of programmable resistor on the buck reg. Not sure if such a thing is readily available but it should be. You could probably use a few FETs shorting out a binary series of resistor values to adjust the voltage divider.

eDiT: Oh geez, here you go...

http://ww1.microchip.com/downloads/en/DeviceDoc/22107a.pdf
(Now that I think about it you could probably use an analog output from the PIC as control voltage on the regulator but that would take some digging into to figure out)

I believe the ASIC has a PLL on board that multiplies 32 MHz up to values between 256 and 300. The cgminer driver has the code that sends two bytes for each hash speed. I documented the values further up this thread.