OT: Building a RISC-V processor out of LSI logic

[scotws]

For those of us thinking they were really ambitious trying to build a 6502 SBC out of little black boxes -- a gentleman by the name of Robert Baruch is building a RISC-V processor out of LSI logic. Yes, a 32-bit processor with 32 registers.

Quote:

The LMARV-1 (Learn Me A Risc-V, version 1) is a RISC-V processor built out of MSI and LSI chips. You can point to pieces of the processor and see the data flow. It should be a nice way of demonstrating how RISC-V works and how simple it is to implement.

He has uploaded a fascinating video https://www.youtube.com/watch?v=yLs_NRwu1Y4 about the first steps, including a (brief) introduction to the RISC-V open ISA CPU, and a discussion about why he chose what chips. It's nice and hardcore, involving things like back-planes and clock signals, resistance values and PCB suppliers. I'm sure some other people here will love it as well.

Oh, and it has blinking lights. Gotta have blinking lights.

For those who haven't heard about RISC-V before, it's a "free and open RISC instruction set architecture", see https://riscv.org/. It's been mostly theoretical so far, but now there is SoC out at https://www.sifive.com/products/hifive1/. Western Digital has announced it will be using, oh, two billion of these things in future hard drives (https://www.anandtech.com/show/12133/we ... ontrollers) and Nvidia is looking to use the architecture for their microcontrollers on their graphics cards (https://www.phoronix.com/scan.php?page= ... Gen-Falcon).

[BigEd]

Excellent - thanks for the links!

[Aslak3]

BigEd wrote:

Excellent - thanks for the links!

Subscribed, thanks very much!

[White Flame]

I watched this a few days ago, and am annoyed that new videos aren't out yet.

[John West]

The project in blog form: http://www.halfbakedmaker.org/blog/lmarv1-1

I thought the name was familiar. He's also behind Project 54/74 https://project5474.org/index.php?title=Main_Page, reverse engineering TTL chips.

[Jmstein7]

Half-baked is right. He never finishes what he starts. Many cool ideas, all dead on the table.

[GARTHWILSON]

Jmstein7 wrote:

Half-baked is right. He never finishes what he starts. Many cool ideas, all dead on the table.

Wow, he does have a lot of cool stuff! As for "half-baked" (the name he gave his own site because he knows that he has a tendency to start things and not finish), yes, it's unfortunate that we all have so many unfinished projects. In fact even in my job, I have a lot of stuff that only got half done before the boss told me to put it aside and work on something else he thought would turn a profit sooner.

[BigEd]

That seems quite a harshly dismissive comment, Jonathan - not the sort of thing we usually see here. It's worth bearing in mind that anyone with a 6502 interest might visit here. You might be insulting a fellow forum member.

[Jmstein7]

BigEd wrote:

That seems quite a harshly dismissive comment, Jonathan - not the sort of thing we usually see here. It's worth bearing in mind that anyone with a 6502 interest might visit here. You might be insulting a fellow forum member.

Ed,

Understood. In actuality, I follow Mr. Baruch - both his blog and his YouTube channel. I enjoy his work a lot. And, he happens to be very humble. As such, he tends to be self-effacing (often), and he himself makes a joke out of the fact that he is always working on one million projects and tends to jump around, and start and stop, regularly. Hence the name "Half-Baked Maker." He's a dabbler - and completely self-taught, at that. His posts have a nice "reality" to them. Very down to earth.

Check out his posts about nMigen; they are quite informative.

Regards,

Jon

[BigDumbDinosaur]

Jmstein7 wrote:

Half-baked is right. He never finishes what he starts. Many cool ideas, all dead on the table.

I have periodically looked at his site and came away with a similar impression. His topic on building a RISC-V processor from discrete gates shows few signs of progress over the last three years.

[BigEd]

Cheers Jon!

One thing that can be surprisingly educational, is when someone who doesn't quite understand what they are doing is able to explain their exploration and learning process, including the dead ends.

[Jmstein7]

BigEd wrote:

Cheers Jon!

One thing that can be surprisingly educational, is when someone who doesn't quite understand what they are doing is able to explain their exploration and learning process, including the dead ends.

It’s more of a “jack of all trades, master of none” problem, you know?