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* shrink the LUT by another bit * correctly use the octant bit to offset the dphi to LUT entry midpoint * add more diagnistics to the unittest and rewrite it in relative units * MSB-align phase and output to match the PLL data, dynamic range and remove the need for roudning bias. * clean up the build.rs table generator a bit
* origin/master: Updating after review Fixing semantics Adding documentation Fixing buffer size Adding updated QSPI stream writer Increasing batch size Adding updates for QSPI streaming Adding WIP refactor Updating DDS control Removing pounder test, adding file Removing unused code Refactoring DDS output control Updating QSPI frequency Adding support for hardware IO_update Fixing merge issues Adding WIP Adding WIP HRTimer Adding WIP experimental code Adding WIP QSPI streaming
Appears to give better code. Test by matthusagh.
matthuszagh
approved these changes
Dec 10, 2020
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remove the need for roudning bias.
Now the quadratic error (the little parabolas), the LUT data quantization error (the scatter) and the phase quantization error (not visible here) all three are of similar magnitude. The max and rms quadrature errors are now 1e-5 and 6e-8 relative to full scale over all possible 20 bit values.
Error in the first octant
FFT at some 120 dBc