--- Quote Start ---
Estimating gate usage on large designs is pretty impossible. Its easier just to implement it. You can usually work out the memory and multiplier requirements though.
--- Quote End ---
Ok. That's not ideal but, well... nothing ever is, really.
--- Quote Start ---
Floating point isnt really suited to FPGAs. you need cores that use a large amount of resources and the latency is higher. fixed point is what FPGAs are good at. you can get a fixed point toolbox for simulink that should help you with that.
--- Quote End ---
*groan* - I
thought that the massively parallel structure would effectively make them good at floating point?!
--- Quote Start ---
The Altera equivolent of the spartan is the Cyclone. Unless you need loads of IO and high speed interfaces, cyclone should be ok for you.
--- Quote End ---
Excellent. I don't need lots of I/O on the FPGA - just the inputs to the delta-sigma ADCs for monitoring phase current and bus voltage, and the encoder inputs for rotor position feedback. All the other i/o will be handled by the supervisory processor (probably one of those Stellaris ARM's with built-in ethernet MAC/PHY).
--- Quote Start ---
But dont underestimate how hard your task is going to be. If you're a software guy...
--- Quote End ---
Ah - I forgot to mention that. I'm the hardware guy. Worse is that my specialty is in high power switchmode conversion so I am probably hopelessly out of my depth here. I already figured that dumping this on our software guy wouldn't be good, and maybe taking it on myself wouldn't be any better, but it is, nevertheless, my responsibility to give this FPGA stuff a fair shake, maybe even the ol' college try, before buying/licensing IP or relying on the free motor control libs from TI for their DSPs.
That said, I still feel that putting the motor control functions into an FPGA is the way to go. It just seems like it will get the job done better and faster. I am basing this on relatively scant information at this point, I will admit, but it just seems right.
Honored Contributor
