Here are the changes made to Canaan's
avalon8-dev branch of their cgminer repository to add support for the A851.
It looks like the A851 may simply be an overclocked version of the A841, judging from the increased base frequency setting (
AVA8_DEFAULT_FREQUENCY_825M) in
line 170 of
driver-avalon8.c in the
avalon8-dev branch. The A841 uses a base frequency setting of
AVA8_DEFAULT_FREQUENCY_775M.
Similarly, the A831 may either be an overclocked version of the A821 or an underclocked version of the A841. The A831 uses a base frequency setting of
AVA8_DEFAULT_FREQUENCY_725M.
The rest of the cgminer code is the same for the A821, A831, A841, and A851.
Note that the addition of support for the A831 and the A851 are in separate branches of Canaan's cgminer repository — code for the A831 is found only in the
avalon8 branch and code for the A851 is found only in the
avalon8-dev branch. This suggests that Canaan may not be looking to release two new models, but may instead be looking to see which model — the A831 or the A851 — would be most viable for release, possibly as a replacement for the preceding model.
On a side note, Canaan also recently
added two new experimental options in the
avalon8-dev branch:
--avalon8-spdlow and
--avalon8-spdhigh. I don't know what
spd stands for, but if it is shorthand for speed, then we may be looking at potential options to select arbitrary levels of lower and upper frequency bounds for the A8s, similar to how we are currently able to set arbitrary voltage levels and voltage level offset values. Both
--avalon8-spdlow and
--avalon8-spdhigh are
configurable using integer values from 0 to 3.
