5 ms·

Can anyone explain the potential benefits of accelerating electronics simulation? Do they want to generate efficient FPGA programs?

kurthr 6y ago
Because all modern computer chips and electronic systems (e.g. PCBs) rely on electrical simulation for design and build. Typically, these are SPICE based simulators, which are open source and quite old in their methods (you literally set convergence requirements and step times). FPGAs are already digital... meaning that although they (FPGAs) have to be simulated when they are designed, their purpose is digital simulation. Programs are at their heart a discrete digital simplification of the underling electrical operation for the purpose of increasing reliability and allowing greater design complexity.
- eternauta3k 6y ago
  Open source? Isn't everyone using Spectre or Eldo?
  - kurthr 6y ago
    which are built on BSD licensed SPICE at Berkeley: "SPICE (Simulation Program with Integrated Circuit Emphasis) is a general-purpose, open-source analog electronic circuit simulator." https://en.wikipedia.org/wiki/SPICE https://en.wikipedia.org/wiki/SPICE Also see HSPICE, pSPICE, LTspice...
KenoFischer 6y ago
Our particular project is about analog simulation, though DARPA is also funding surrogate modeling efforts in the digital domain. On analog in particular, one significant impetus is speeding up mixed signal simulations, since digital simulators (in terms of seconds of execution simulated per seconds of simulation time) are much faster than analog simulators, so if you want to do a mixed signal simulation, you're generally running it at the speed of analog simulators. For end-to-end simulation, it would be much nicer if you could bring up the speed of the analog simulators to be comparable to the digital simulators. Of course there is a question of how much accuracy you're paying (and we're still finding out what the tradeoff is), but in the kinds of simulations where this comes in, your actually often ok with losing some accuracy, since you can always get some noise coupled into the analog portion, so your control electronics should be robust to slightly weird analog signals anyway.
- ThJ 6y ago
  i've had a lot trouble with analog simulations in SPICE. they often fail to converge or run incredibly slowly. i do a lot of audio circuitry. the speedups addressed here could potentially make it possible to simulate audio circuits in real time. suppose you feed a signal in via an audio interface, pass it through your analog processing circuitry and play it back in real time. the design cycle would be so much faster.
  - ThJ 6y ago
    speaker frequency response simulations will sometimes use an equivalent electronic circuit. it could help design better speakers. any time you interface digital circuitry with the real world, hybrid circuitry is used. also, with this increased processing capacity, you could be looking at simulating the parasitic properties of components, not just ideal versions of them.
  - ThJ 6y ago
    many sims use some variety of SPICE and some convergence algorithm a-la Newton's method to discover the voltages and currents at the nodes. simulating a system where every single component runs in parallel with every other component isn't easy.
  - KenoFischer 6y ago
    We are working on improvements to the baseline simulator also (or rather we basically get them for free because they are part of our core simulation engine), so hopefully that should address some of the first order usability issues in SPICE simulations. For these kinds of design applications, the ML-based speed up may or may not work, since you do have to spend time training the surrogate. You can often re-use pieces of if, but depending on what kind of manipulations you're doing to the model you're surrogatizing, it may or may not help if you're changing the circuit after every simulation.
    - ptarmigan 6y ago
      Sorry if you've already clarified, but is this meant to replace or augment traditional SPICE simulators? I remember Ken Kundert mentioned that, even with the improvements of Spectre over SPICE-based simulators, it took things like SpectreRF's oscillator phase noise modeling to get analog designers to consider changing their ways. Their steadfast use of SPICE is "a form of Stockholm Syndrome," in his own words.
hctaw 6y ago
Accelerate doesn't just mean 'run faster' but 'write models faster.' It's about reducing time to market and overhead for design verification, which is a massive time and money sink in the industry today.

kurthr 6y ago

Because all modern computer chips and electronic systems (e.g. PCBs) rely on electrical simulation for design and build. Typically, these are SPICE based simulators, which are open source and quite old in their methods (you literally set convergence requirements and step times). FPGAs are already digital... meaning that although they (FPGAs) have to be simulated when they are designed, their purpose is digital simulation. Programs are at their heart a discrete digital simplification of the underling electrical operation for the purpose of increasing reliability and allowing greater design complexity.

eternauta3k 6y ago
Open source? Isn't everyone using Spectre or Eldo?
- kurthr 6y ago
  which are built on BSD licensed SPICE at Berkeley: "SPICE (Simulation Program with Integrated Circuit Emphasis) is a general-purpose, open-source analog electronic circuit simulator." https://en.wikipedia.org/wiki/SPICE https://en.wikipedia.org/wiki/SPICE Also see HSPICE, pSPICE, LTspice...

KenoFischer 6y ago

Our particular project is about analog simulation, though DARPA is also funding surrogate modeling efforts in the digital domain. On analog in particular, one significant impetus is speeding up mixed signal simulations, since digital simulators (in terms of seconds of execution simulated per seconds of simulation time) are much faster than analog simulators, so if you want to do a mixed signal simulation, you're generally running it at the speed of analog simulators. For end-to-end simulation, it would be much nicer if you could bring up the speed of the analog simulators to be comparable to the digital simulators. Of course there is a question of how much accuracy you're paying (and we're still finding out what the tradeoff is), but in the kinds of simulations where this comes in, your actually often ok with losing some accuracy, since you can always get some noise coupled into the analog portion, so your control electronics should be robust to slightly weird analog signals anyway.

ThJ 6y ago
i've had a lot trouble with analog simulations in SPICE. they often fail to converge or run incredibly slowly. i do a lot of audio circuitry. the speedups addressed here could potentially make it possible to simulate audio circuits in real time. suppose you feed a signal in via an audio interface, pass it through your analog processing circuitry and play it back in real time. the design cycle would be so much faster.
- ThJ 6y ago
  speaker frequency response simulations will sometimes use an equivalent electronic circuit. it could help design better speakers. any time you interface digital circuitry with the real world, hybrid circuitry is used. also, with this increased processing capacity, you could be looking at simulating the parasitic properties of components, not just ideal versions of them.
- ThJ 6y ago
  many sims use some variety of SPICE and some convergence algorithm a-la Newton's method to discover the voltages and currents at the nodes. simulating a system where every single component runs in parallel with every other component isn't easy.
- KenoFischer 6y ago
  We are working on improvements to the baseline simulator also (or rather we basically get them for free because they are part of our core simulation engine), so hopefully that should address some of the first order usability issues in SPICE simulations. For these kinds of design applications, the ML-based speed up may or may not work, since you do have to spend time training the surrogate. You can often re-use pieces of if, but depending on what kind of manipulations you're doing to the model you're surrogatizing, it may or may not help if you're changing the circuit after every simulation.
  - ptarmigan 6y ago
    Sorry if you've already clarified, but is this meant to replace or augment traditional SPICE simulators? I remember Ken Kundert mentioned that, even with the improvements of Spectre over SPICE-based simulators, it took things like SpectreRF's oscillator phase noise modeling to get analog designers to consider changing their ways. Their steadfast use of SPICE is "a form of Stockholm Syndrome," in his own words.

hctaw 6y ago

Accelerate doesn't just mean 'run faster' but 'write models faster.' It's about reducing time to market and overhead for design verification, which is a massive time and money sink in the industry today.