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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?

#81

Post by sliverstorm »

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…

But, if you want to make a high performance netlist, I'd argue you want to know all about logic gates, Boolean math, and all the rest. HDL stands for "hardware description language", and you'll only write good HDL if you know what you're writing looks like in gates.

(Though if you're just making an LED blink when you push a button, you don't need to write good HDL)

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

#82

Post by spear »

gluggymug wrote: post #69
pslam wrote: post #48

Earlier quoted context omitted.

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.

I don't agree. If it's non trivial, I don't have the more advanced verification tools such as UVM if I prototype via FPGA. The ability to perform constrained randomised verification is only workable via UVM or something like it. For large designs that is arguably the best verification methodology. Without visibility through the design to observe and record the possible corner cases of transactions, you can't be assur…

That's a false dichotomy -- you can do FPGA verification in addition to simulation-based verification. And yes, there are ASIC teams that have successfully done that.

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

#83

Post by kregasaurusrex »

kregasaurusrex wrote: post #7
nimish wrote: post #5

Get yourself an FPGA devkit and start making little hardware bits

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…

Edit: Thanks a lot for the info everyone.

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

#85

Post by deepnotderp »

sandGorgon wrote: post #35

Its quite late here, so I'll be brief. You mentioned the words "how IP is managed in chip industry" - so I'm going to move past the bookish knowledge and the tutorials and the open source code. The chip design and EDA industry are very closeted and niche - there is so much knowledge there that is not part of any manual. For example for a newcomer, you wouldn't even know what testing and validation in chip design woul…

While I agree that the semiconductor industry is crushingly conservative, it's not necessarily that bad. You can still use many of the "old classics", you just have to remember that instead of 10 design rules there are 10K ;)

In all honesty though, a significant amount of the complexity can be hidden in the eda layers nowadays, and instead of dealing with the er,"tenacious"- synthesis tools, you can use good alternatives like Chisel.

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

#86

Post by flying_sheep »

First of all you must understand logic gates, flip-flops (D-FF, T-FF and so on) and multiplexers. All of them are built on logic gates. To verify that you really understand the concept, try to implement a digital clock. (This one: https://sapling-inc.com/wp-content/gallery/digital-clocks-fo...)

Logic gates are essential of learning digital circuits. After you understand logic gates, you can use it to build many things that are really related to the application. There are many tools to verify the logic gates works as designed.

Then based on the project requirement ($$, time, performance, ...), you can choose to use FPGA or ASIC to implement logic gates. FPGA use array of logic gates while ASIC uses CMOS to implement the logic gates. FPGA is easier to learn and much cheaper. You can buy some development board which costs only several hundred dollars. While ASIC needs much domain knowledge and people involved. ASIC needs you to understand the electronics in order to build something that is useful. You need to understand how the CMOS are implemented (= how semiconductor becomes conductive), how the resistance and capacitance affect the performance, the number of wafer layout which affects the cable layout and more. And don't forget manufacturing can introduce defeats which cause the IC to malfunction in unexpected ways. Each step in ASIC needs a specialist for them

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

#87

Post by taneq »

mikeash wrote: post #79
DigitalJack wrote: post #77

Earlier quoted context omitted.

I don't think it's that bad. Board design is, but if you are working with some standard board, say from Opal Kelly (no affiliation), then you don't have to worry about that. But what about the DRM with HDMI? I have no idea how it works, but I assumed the signal was encrypted.

HDCP (the DRM tech for HDMI) was not very well designed, and the master keys were cracked some years ago.

Which is probably fine if you're just doing it as a hobby project, but could land you in a legal pickle if you try to do anything commercial with it.

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

#88

Post by deepnotderp »

cottonseed wrote: post #30
jleahy wrote: post #16

Earlier quoted context omitted.

You can actually get an ASIC manufactured for a few thousand dollars via CMP or Europractice. So not quite Google money. The difficulty is in paying for the software licenses you need to go from Verilog to DRC checked GDSII files (which is what you need to send to them). In fact personally I think this is a much better route for open source hardware. Reverse engineering FPGA bitstreams impressive, but you're swimming…

There's also efabless: https://efabless.com/ Europractice has prices online: http://www.europractice-ic.com/general_runschedule.php

MOSIS is also an option in the US, albeit more geared towards industry.

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

#89

Post by deepnotderp »

gluggymug wrote: post #69
pslam wrote: post #48

Earlier quoted context omitted.

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.

I don't agree. If it's non trivial, I don't have the more advanced verification tools such as UVM if I prototype via FPGA. The ability to perform constrained randomised verification is only workable via UVM or something like it. For large designs that is arguably the best verification methodology. Without visibility through the design to observe and record the possible corner cases of transactions, you can't be assur…

This reflects my experience. Many/most of the "nontrivial" issues nowadays are rooted in physical issues, not logical issues. And in those cases, simulation is often superior to dealing with the fpga software layer. Fwiw,I asked my co founder formerly at Intel, and he said that fpga involvement was "almost zero".

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

#90

Post by exikyut »

mikeash wrote: post #79
DigitalJack wrote: post #77

Earlier quoted context omitted.

I don't think it's that bad. Board design is, but if you are working with some standard board, say from Opal Kelly (no affiliation), then you don't have to worry about that. But what about the DRM with HDMI? I have no idea how it works, but I assumed the signal was encrypted.

HDCP (the DRM tech for HDMI) was not very well designed, and the master keys were cracked some years ago.

Ah, TIL. I thought HDCP was still a wall. Security by Committee™ FTW!
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