[Libre-soc-dev] daily kan-ban update 08sep2020
colepoirier at gmail.com
Tue Sep 8 21:02:31 BST 2020
On Tue, Sep 8, 2020 at 12:33 PM <whygee at f-cpu.org> wrote:
> On 2020-09-08 17:21, Luke Kenneth Casson Leighton wrote:
> > therefore: rather than route 192+ wires across entire swathes of the
> > chip (to 12 separate pipelines), all you do is *PARTIALLY* decode the
> > instruction (enough to know which pipeline to deliver to), then route
> > the *raw* instruction (only 32-bit) over to the pipeline, and have it
> > *locally* decode *ONLY* the instruction fields that it actually needs.
> > this does mean however that immediates get decoded more than once, for
> > example. given that it's local, i'm not concerned about that. it's
> > the number of wires crossing the chip that's got to come down.
> > l.
> it seems like a good move to me because this would also decrease power
> other things, through easier routing, lower capacitance load, ...
> CDC6600s were hand-wired in 3D but our chips are limited to 2D (2.5D
> the metal layers). It made sense for a CDC6600 to have all the bits
> and taken directly to the units, because transistors were expensive.
> Today, routing is a major bottleneck, particularly at that scale...
This may just be due to my noobieness, but reading this earlier this
morning my jaw was slightly agape and I was thinking "Wow that's so
elegant and so freaking cool!".
Congratulations on getting it working Luke!
Luke, I uploaded the CR-XER debug vhdl interface that I did the new
version of yesterday
Worked on icache.vhdl about 10% to go.. 15% if I include icache_tb.vhdl.
Fixed the remaining issues in the libre-soc vulkan driver setup, there
were necessary files missing from the src/libre-soc/vulkan dir but
copying the files that meson errored on not finding from
src/amd/vulkan to src/libre-soc/vulkan allowed me to compile and
install successfully. Do we have a copy hosted on git.libre-soc.org,
or should I be making a pull request to vivek's branch on the
Updated the wiki documentation page for this, and updating the
associated script now, will push shortly.
Finish icache.py first translation pass.
Review luke's comments on D-Cache if I have time.
More information about the Libre-soc-dev