Live data from Hacker News

Amid chip shortages, companies bet on RISC-V

allaboutcircuits.com

111–120 of 129 posts

Re: Amid chip shortages, companies bet on RISC-V

#111

Earlier quoted context omitted.

You want to have lots of software for your computer. Like Linux, Chromium, compilers, JIT, etc. It reduces the number of options.

Most hardware is not field-programmable. You can't update a CPU's DDR3 PHY to DDR4, or switch to DDR3L if your needs change. The single-purpose nature of ASICs and hardware blocks is what makes them fast and power-efficient.

Yeap! I've worked with analog and digital chip designers, along with some digital designers that now work on fundamental IP for an FPGA company. One thing they all had in common was "we avoid all abstractions". It's all as direct as possible. You don't use extra silicon to appease some tidy block diagram that makes the problem easier to reason about, because the silicon isn't made for humans to reason about, it's made for holes and electrons to do their thing!

Re: Amid chip shortages, companies bet on RISC-V

#112

Earlier quoted context omitted.

What's the difference between desktop and embedded? I reverse-engineered some medical device. It houses tiny CPU and 3" touch screen. Inside it runs Linux with X Window, Chromium, Electron and software written with JS. It's definitely embedded device, it's tiny, works from accumulator, hand-held. But its software stack is not any different from desktop.

Traditionally, the main difference was a full-featured MMU which allows virtual address spaces. But these days, you have advanced 600MHz microcontrollers with simple GPUs, and full-featured CPUs which get used as an embedded platform. You can even build a Linux kernel for no-MMU platforms. It's a fuzzy line.

Could you please name some of the microcontrollers that you are referring to?

Re: Amid chip shortages, companies bet on RISC-V

#113

Earlier quoted context omitted.

Why do you call them "spy" chips? Have they been found to generally have backdoors? In an embedded context, a lot of that doesn't matter either way - your dumb coffee maker doesn't have a lot of opportunity to spy on you anyway. Smart devices are a very different story. However, Chinese embedded chips are often very cheap for the capabilities.

And all Intel and AMD processors have "spy" capabilities too with the built-in black-box Intel Management Engine and AMD Platform Security Processor. And it's only becoming more powerful and commonplace with remote attestation and Microsoft Pluton. In a few years PCs might become just like mobile phones - the bootloader locked down requiring signed images from Microsoft, etc. Given all of that, China seems like a gre…

In a few years PCs might become just like mobile phones - the bootloader locked down requiring signed images from Microsoft, etc.

The number of Windows-exclusive programs are rapidly dwindling. In a few years, it may not be such a big deal to simply avoid that with Linux (or FreeBSD).

Re: Amid chip shortages, companies bet on RISC-V

#114

Earlier quoted context omitted.

The stolen architectures cannot be legitimately sold outside of China, due to patents held by ARM ltd. RISC-V avoids these headaches.

Indeed, but conversely, China will have access to ARM no matter what. This also means that we can sanction all we want, they locally have the fabs and IP to create ARM, RISC-V, MIPS and even x86 CPUs (and they are already doing all of that). Granted, their fabs can't do top-of-the-line lithography (yet?) but since they have already created 64-core ARM server CPUs and some custom AI silicon they can get horizontally s…

China wants to sell chips and gadgets with chips inside. Legally questionable access to ARM will not help with that. RISC-V solves the problem.

Re: Amid chip shortages, companies bet on RISC-V

#116
post #70

Earlier quoted context omitted.

Does anyone outside of China want Chinese spy chips regardless of architecture?

Tons of hobbyists buy PINE hardware. All of their SoCs are Chinese (Rockchip, Allwinner). Hardkernel/Odroid stuff is a mix of Amlogic, Intel, and Rockchip. Outside the hobbyist space people do seem to be shunning Chinese SoCs AFAICT. Maybe no name TV boxes have rockchips, but other than that not much.

What non-Chinese options do hobbyist boards have? NXP chips seems almost impossible to get for the hobbyist market. I’m not sure why. Broadcom for the RPI’s we’re probably only possible because the creators had worked at Broadcom.

Re: Amid chip shortages, companies bet on RISC-V

#117

Earlier quoted context omitted.

Traditionally, the main difference was a full-featured MMU which allows virtual address spaces. But these days, you have advanced 600MHz microcontrollers with simple GPUs, and full-featured CPUs which get used as an embedded platform. You can even build a Linux kernel for no-MMU platforms. It's a fuzzy line.

Could you please name some of the microcontrollers that you are referring to?

check out NXP i.MX RT1060

Re: Amid chip shortages, companies bet on RISC-V

#118

Earlier quoted context omitted.

In addition to RISC-V being more flexible than ideal here, PowerPC is more complicated as an instruction set which is a drawback if you're a student learning to implement your first processor or in a deeply embedded role. But given the huge amount of effort that goes into a high performance core it gets lost in the noise and it lets you execute tasks in fewer instructions without crazy difficult to implement levels o…

RISC-V does not in any way depend on instruction fusion. I don't why this meme persists, especially as no RISC-V cores in the market do instruction fusion. High end OoO cores in other ISAs are BREAKING DOWN complex instructions into µops. RISC-V is pre-broken down. The one exception to that is current x86 and ARM cores DO do instruction fusion, to combine a compare with a following conditional branch. Which is a sing…

The meme persists because the ISA has a lot of “simple” instructions that don’t actually match what real world software would like to make performant, so a bunch of RISC-V enthusiasts handwave it away as “oh the chip will just fuse all the instructions and make it efficient”.

Re: Amid chip shortages, companies bet on RISC-V

#119
post #107

Earlier quoted context omitted.

Indeed, but conversely, China will have access to ARM no matter what. This also means that we can sanction all we want, they locally have the fabs and IP to create ARM, RISC-V, MIPS and even x86 CPUs (and they are already doing all of that). Granted, their fabs can't do top-of-the-line lithography (yet?) but since they have already created 64-core ARM server CPUs and some custom AI silicon they can get horizontally s…

They do have access to ARM, sure. But they also have access to RISC-V, which is technically superior and free of the troubles associated with ARM.

What is superior about RISC V technically?

Re: Amid chip shortages, companies bet on RISC-V

#120
post #95

Earlier quoted context omitted.

Apple wouldn't have used ARM for the iPhone and iPad if the cores hadn't been proven in other similar platforms. ARM goes back a long time. My Psion palmtops have ARM cores. Many of the WinCE systems have ARM cores. The ARM processors in fact go back to 1985, with the ARM Development System for the BBC Micro and then the Archimedes in 1987. There's a whole world of ARM processors out there. The ISA, packaging, softwa…

At the very first moment that there was a company called "ARM", in 1991, Apple owned 1/3 of it, the other partners being Acorn(who invented it) and VLSI Technology (who made the chips). Psion adopted a CPU Apple was using in, AND A COMPANY THEY OWNED developed for, the Newton and eMate, not the other way around. The ARM710 used in the Series 5 was the same as Apple used in the eMate.

Since that time, there was a point Apple was nearly bankrupt. Also since then they partnered on another new processor technology and put that one in the Mac. Then they got rid of that one and went to Intel chips. Only recently did they develop an ARM core they considered superior to the desktop competition. The whole Newton/eMate line were nice but were marketplace flops.

Apple plays a long game, but saying they funded ARM in the mid 1980s so they could slowly grow those cores by themselves for themselves in 2020 and later ignores a whole lot of history about both Apple and ARM.

Post reply on HN