From: Luke Kenneth Casson Leighton Date: Sat, 28 Sep 2019 05:02:51 +0000 (+0100) Subject: add to intriguing ideas X-Git-Url: https://git.libre-soc.org/?p=crowdsupply.git;a=commitdiff_plain;h=a8e603dce20e5abf6a5e205d5c63a68ea56d7237 add to intriguing ideas --- diff --git a/updates/020_2019aug28_intriguing_ideas.mdwn b/updates/020_2019aug28_intriguing_ideas.mdwn index e975613..c2eb5bd 100644 --- a/updates/020_2019aug28_intriguing_ideas.mdwn +++ b/updates/020_2019aug28_intriguing_ideas.mdwn @@ -5,6 +5,8 @@ We decide to go with a "reconfigurable" pipeline; # The possibility of a 3D Open Graphics Alliance +{https://youtu.be/HeVz-z4D8os} + At SIGGRAPH 2019 this year there was a very interesting BoF, where the [idea was put forward] (https://www.pixilica.com/forum/event/risc-v-graphical-isa-at-siggraph-2019/p-1/dl-5d62b6282dc27100170a4a05) @@ -59,11 +61,13 @@ markets, it is no good creating an ISA that has such a high barrier to entry and such a power-performance penalty that it inherently excludes the very implementors it is targetted at, particularly in Embedded markets. -These are the challenges to be discussed at the upcoming first +Thus we need a Hybrid Architecture, not just to reduce complexity, not +just to meet Libre criteria, but to meet the long tail of innovation in +3D and kick start some real innovation. +These were the challenges discussed at the upcoming first [meetup](https://www.meetup.com/Bay-Area-RISC-V-Meetup/events/264231095/) -at Western Digital's Milpitas HQ. - -https://youtu.be/HeVz-z4D8os +at Western Digital's Milpitas HQ. Experts in 3D at the Meetup were really +enthusiastic and praised this approach. # Reconfigureable Pipelines @@ -93,8 +97,9 @@ It turns out that by using what is termed "transparent latches" that it is possible to do precisely that.  The advantages are enormous and were described in detail on comp.arch -https://groups.google.com/d/msg/comp.arch/fcq-GLQqvas/SY2F9Hd8AQAJ   -Earlier in that thread, someone kindly pointed out that IBM published +Earlier in +[this thread](https://groups.google.com/d/msg/comp.arch/fcq-GLQqvas/SY2F9Hd8AQAJ), +someone kindly pointed out that IBM published papers on the technique.  Basically, the latches normally present in the pipeline have a combinatorial "bypass" in the form of a Mux. The output is dynamically selected from either the input *or* the input after it @@ -112,3 +117,42 @@ impact on instruction latency. It's a fantastic idea that will allow us to reconfigure the processor to reach a 1.5ghz clock rate for high performance bursts. +# NLNet Funding proposals. + +The next step is to put in half a dozen NLNet Funding proposals. No, +literally: +[seven new proposals](https://libre-riscv.org/nlnet_proposals/), +each for EUR 50,000. One for gcc, one for a port of MESA RADV to the +new processor, another for writing experimental assembly code to go into +libswscale, libx264 etc. ultimately for use in VLC and ffmpeg and so on. + +Best of all, two for actually doing a test ASIC: one working with +chips4makers, the other with lip6.fr. It turns out that 180nm ASIC shuttle +services cost only USD 600 per square mm, and we can get away with around +20 sq.mm which is about USD 12,000 and estimated 800,000 gates. + +At that low cost, we can iterate before going to lower geometries plus +actually have something which, even at 350mhz, if it was dual issue, +would be a reasonable saleable product in its own right. The only thing +we have to watch out for, there, is that it will be a bit of a monster +so power consumption is going to be high at 350mhz. Still, for a first +ASIC ever, it's just exciting to think that it's possible at all. + +Regarding the NLNet proposals: we need people! In particular, we need two +EU Citizens to come forward, to satisfy NLNet's backers' requirements +(Thanks to [NGU.eu](https://ngi.eu), NLNet has received its money under +the EU Horizon 2020 Programme), so at least one EU Citizen has to be +part of the proposal. One for gcc, another for the MESA/RADV port. +Please do contact me for details. There's no contract or obligation, +because this is charitable donations. + +In addition, if anyone wants to receive tax deductible charitable +donations direct from NLNet for working on aspects of this project, +do get in touch, there is plenty to do. Application reviews start in 2 +weeks, we will hear from NLnet by December as to what has been approved, +and will be able to expand the project scope around January 2020. + +Also remember, if you work for a Corporation that could financially +benefit from this project being a reality, sponsorship, via NLNet, +is tax deductible because it is a charitable donation. +