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Ask HN: Where do I get started on ASICs, FPGA, RTL, Verilog et. al?

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Re: Ask HN: Where do I get started on ASICs, FPGA, RTL, Verilog et. al?

#41

Post by gluggymug »

As a veteran from the chip industry, I should warn you that all these suggestions about FPGAs for prototyping are not really done that much in the ASIC industry.

The skills to do front end work are similar but an ASIC design flow generally doesn't use an FPGA to prototype. They are considered slow to work with and not cost effective.

IP cores in ASICs come in a range of formats. "Soft IP" means the IP is not physically synthesised for you. "Hard IP" means it has been. The implications are massive for all the back end work. Once the IP is Hard, I am restricted in how the IP is tested, clocked, resetted and powered.

For front end work, IP cores can be represented by cycle accurate models. These are just for simulation. During synthesis you use a gate level model.

Re: Ask HN: Where do I get started on ASICs, FPGA, RTL, Verilog et. al?

#42

Post by lvoudour »

KSteffensen wrote: post #13
kregasaurusrex wrote: post #7

Earlier quoted context omitted.

What's the best way for a novice to determine what their needs are? One thing that's been a barrier to entry for me has been fear of vendor lock-in from point of sale with regards to upgrading in the future; ie: purchasing a starter kit by company X but once determining that only company Y supports the feature set. Where there would then require a non-trivial amount devtime would be sunk in re-tooling your code both…

If you're worried about vendor lock-in, FPGA/ASIC design is not for you. The design tool market is horrible. That said, for a novice there are no significant differences in features between Altera and Xilinx. The place where you might see problems is mostly in simulation, where the big three tool vendors support different language features in SystemVerilog and VHDL-2008. Again, this is not likely to be a problem for…

>The design tool market is horrible

I wouldn't say it's horrible, it's just not open source (mainly because it's mostly a high-end market). You can easily get by with the free versions of the implementation/simulation tools if you're a hobbyist

Re: Ask HN: Where do I get started on ASICs, FPGA, RTL, Verilog et. al?

#43

Post by jleahy »

exikyut wrote: post #32

I've gotten curious about FPGAs myself of late, particularly with video capture. A hopefully-on-topic question of my own, if I may: I've seen that some FPGA boards have HDMI transceivers that will decode TMDS and get the frame data into the FPGA somehow. That got me thinking about various possibilities. - I want to build a video capture device that will a) accept a number of TMDS (HDMI, DVI, DisplayPort) and VGA sign…

This is a very difficult project.

No FPGAs have anything to decode TMDS. What they have is transceivers that will take the multi-gigabit serial signal and give it to you 32-bits or 64-bits at a time. Then it's your job to handle things like bit alignment, 8b10b decoding, etc. You need 6MB of RAM to hold one frame at 1080p, and to do this you'll need to hold one for each input. That requires external RAM (there's no enough on the FPGA), which means you'd need something like 30Gbit/sec of RAM bandwidth, which means you need DDR2 RAM before you've even stored anything (DDR3 is really awkward, I'd stick to DDR2 or LPDDR2, DDR4 is going to be impossible).

I'm not even going to comment on the feasibility of implementing SATA.

Re: Ask HN: Where do I get started on ASICs, FPGA, RTL, Verilog et. al?

#45

Post by ChuckMcM »

mcshicks wrote: post #26
ChuckMcM wrote: post #2

There are three things here that you've intertwined. Process -- This is the science of creating circuits on silicon wafers using lithography, etching, and doping. There is a large body of knowledge around the physics involved here. Materials science and Physics and Silicon Fabrication are all good places to start. Chip Design -- This is creating circuits which are run through a tool that can lay them out for you auto…

Yes that's true, but there's actually even more like packaging, testing, etc. I took a free online course from Stanford called "nanomanufacturing" but it really was mostly about about chip manufacturing, packaging etc. Even though I worked in the semiconductor industry for 12 years (mostly bench testing preproduction ASICS) I still found it really useful. Not sure if you can still view the archives here if you sign u…

That is awesome. The link doesn't work for me but I didn't really expect it to. My first job in the Bay Area was working for Intel and about 6 months in I was offered some 'counterfeit' or grey market Intel DRAM chips. (as a microcomputer enthusiast, not as an Intel employee) I took the offer to security, who gave me the cash to buy a tube of them, which I did, and they disassembled them to figure out where in the packaging pipeline they had gone missing.

Sadly I never got to hear the full story on how they came to be but I did get a good look at the packaging pipeline that Intel used at the time. It was extensive even then with half a dozen entities providing steps in the path.

Re: Ask HN: Where do I get started on ASICs, FPGA, RTL, Verilog et. al?

#46

Post by pslam »

jleahy wrote: post #4

I wouldn't get too hung up on the phrase 'IP core', it's basically the equivalent of a software library. A reusable chunk of silicon or verilog. If you want to know about how chips are made then I'd highly recommend the book "CMOS Circuit Design and Simulation" by Baker. It's starts off telling you how silicon is etched to make chips, then goes through how MOSFETs work and how to simulate them using SPICE. By the tim…

> If you want to know about how chips are made then I'd highly recommend the book "CMOS Circuit Design and Simulation" by Baker.

This is a ~$120 book. Do you (or anyone else) have a recommendation for something a little easier to tell hobbyists they should get?

Re: Ask HN: Where do I get started on ASICs, FPGA, RTL, Verilog et. al?

#47

Post by jwatte »

You can start by buying a Papillon board and going through the free range VHDL book. That's the high level.

When you want to understand CMOS and integrated circuits, you need some electronics experimenter kit, and a lot of practice in ohms law. Then read up on multiple gate transistors and (here my experience stops) lithography and small scale challenges (tunneling loss is a thing, I suppose?)

Of course, "ip core" can mean different things, might be some Verilog source, might be some netlists, might be a hard macro for a particular process. You really need to work with it to get the specifics. (Subscribing to EETimes, going to trade shows, and otherwise keeping up might help)

But at the end of the day, you're asking "how can I become and experienced ASIC engineer," and the truth is that it takes time, education, and dedication.

Re: Ask HN: Where do I get started on ASICs, FPGA, RTL, Verilog et. al?

#48

Post by pslam »

gluggymug wrote: post #41

As a veteran from the chip industry, I should warn you that all these suggestions about FPGAs for prototyping are not really done that much in the ASIC industry. The skills to do front end work are similar but an ASIC design flow generally doesn't use an FPGA to prototype. They are considered slow to work with and not cost effective. IP cores in ASICs come in a range of formats. "Soft IP" means the IP is not physical…

As a veteran from the chip industry, I can tell you my experience is completely the opposite.

Nobody in their right mind would produce an ASIC without going through simulation as a form of validation. For anything non-trivial, that means FPGA.

Re: Ask HN: Where do I get started on ASICs, FPGA, RTL, Verilog et. al?

#49

Post by hak8or »

pslam wrote: post #46
jleahy wrote: post #4

I wouldn't get too hung up on the phrase 'IP core', it's basically the equivalent of a software library. A reusable chunk of silicon or verilog. If you want to know about how chips are made then I'd highly recommend the book "CMOS Circuit Design and Simulation" by Baker. It's starts off telling you how silicon is etched to make chips, then goes through how MOSFETs work and how to simulate them using SPICE. By the tim…

> If you want to know about how chips are made then I'd highly recommend the book "CMOS Circuit Design and Simulation" by Baker. This is a ~$120 book. Do you (or anyone else) have a recommendation for something a little easier to tell hobbyists they should get?

It depends on what sort of asic stuff fyou want to do, meaning digital or analog.

Adanced chip design by kishore Mishra is very good and like 50 bucks last I remember.

If I were you, I would just look at Amazon reviews and buy whatever looks decently rated and is avalible for cheap used.

Re: Ask HN: Where do I get started on ASICs, FPGA, RTL, Verilog et. al?

#50

Post by jwatte »

jsolson wrote: post #21
namibj wrote: post #17

Earlier quoted context omitted.

If i correctly understand what you are saying, it cold pe possible to make a custom small chip for doing some crypto capable of a little more than what those smartcards offer for under 10k$? That would be awesome, from a trust perspective, at least if you could realistically compare the chip you get back with what you know to expect, using an electron microscope.

Not for an ASIC without spending a LOT on tooling, and really $10k is awfully optimistic even if you had all of that tooling (I probably should've just said tens of thousands). For Honestly, you might be better off just buying functional ICs (multi-gate chips, flip flops, shift registers, muxes, etc.) and making a PCB, though. Most crypto stuff is small enough that you can do a slow/iterative solution in fairly small…

If you do that, why wouldn't you use a FPGA or just a fast CPU? Microcontrollers and CPUs are blending in performance, and are cheap enough to plop on a board and call it done for many applications.
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