Fast VHDL CORDIC Sine and Cosine Component on Lattice XP2 Device Using Diamond 3.12 Part 2

RE: Fast VHDL CORDIC Sine and Cosine Component on Lattice XP2 Device Using Diamond 3.12 Part 2

jc2048 — Sun, 07 Jun 2026 14:46:24 GMT

Here is the sine and cosine in more detail

and here's the spectrum view

with, and this surprised me, a THD figure of 0.005% (if you look closely, there isn't anything much at the actual harmonics). So the CORDIC calculation of the sine must be fairly accurate. Presumably the other lines, clustered around the fundamental, are intermodulation products (but what would be the source of the interference?).

RE: Fast VHDL CORDIC Sine and Cosine Component on Lattice XP2 Device Using Diamond 3.12 Part 2

scottiebabe — Wed, 18 Feb 2026 16:04:42 GMT

Very neat, I am experimenting with running an sdr on a pico and eventually will have to pick a fast atan2 approximation

RE: Fast VHDL CORDIC Sine and Cosine Component on Lattice XP2 Device Using Diamond 3.12 Part 2

DAB — Tue, 17 Feb 2026 20:32:17 GMT

Nice update.

RE: Fast VHDL CORDIC Sine and Cosine Component on Lattice XP2 Device Using Diamond 3.12 Part 2

michaelkellett — Tue, 17 Feb 2026 10:23:13 GMT

Nice to see an FPGA project at the register level in VHDL.

Good luck with the iCE40 - its a useful part - (I just did a customer design on one recently) but pretty weedy by modern FPGA standards.

On the other hand they are cheap, available in 48 pin QFN packages and use almost no power.