LabVIEW FPGA polynom

[bahec666]

Hello. I have FlexRIO board PXIe-7966R. I'd like to calculate polynom of input data: 0.2139*x^3 - 0.0684*x^2+0.9524*x+0.0085 , where x - is I16 input data.

But i have a problem, that this calculating takes a lot of time - 20MHz. I'd like to execute this operation in single cycle timed loop with 125MHz clock. How can i optimize this operation? 

[Intaris]

Pipelining.

[mikeporter]

Well, given that the input is an integer there is just a finite number of possible answers to the calculation (65,536 to be precise). Could you do it as a lookup table?

Does your input use the entire 16-bit dynamic range? If not, you might need able to trim that number down a bit.

Mike...

[Intaris]

Another thing to take note of, what's your required latency?  If your calculated value cannot be more than 1 cycle delayed from your input then LUT (as mike pointed out) is going to be the only way.

[David-A]

The NI LabVIEW High-Performance FPGA Developer's Guide discusses how to use the SCTL, and how it can be used to optimize throughput and minimize latency.