FFT and FHT engine
A transformation engine includes an address generator; a butterfly unit coupled to the address generator; a twiddle LUT coupled to the address generator; and a multiplier having a first input coupled to the butterfly unit and a second input coupled to the twiddle LUT.
1. A transformation engine, comprising:
an address generator;
a butterfly unit coupled to the address generator, the butterfly unit to compute fast Hadamard transform (FHT) operations;
a twiddle LUT coupled to the address generator; and
a multiplier having a first input coupled to the butterfly unit and a second input coupled to the twiddle LUT.
2. The engine of claim 1 , wherein the butterfly unit is further controlled to compute fast fourier transform (FFT) operations.
3. The engine of claim 1 , wherein the butterfly unit is further controlled to compute decimation in frequency fast fourier transform (DIF FFT) operations.
4. The engine of claim 1 , wherein the twiddle LUT contains twiddle factors set to one.
5. The engine of claim 1 , wherein input data belonging to FHT samples are mapped to predetermined inputs of the transformation engine.
6. The engine of claim 1 , further comprising an input buffer coupled to the butterfly unit.
7. The engine of claim 1 , further comprising an output buffer coupled to the multiplier.
8. A method for performing a plurality of transformations, comprising:
determining a transformation operation to be performed on data; and
sharing a transformation engine between multiple transformation operations including a fast Hadamard transformation (FHT) operation via setting twiddle factors to one.
9. The method of claim 8 , further comprising setting the engine to select the transformation operation.
10. The method of claim 8 , further comprising receiving an output of the transformation operation on the data.
11. The method of claim 8 , further comprising selecting the transformation engine to perform FFT or FHT operations.
12. The method of claim 8 , further comprising mapping input data belonging to FHT samples to predetermined inputs of the transformation engine.
13. The method of claim 12 , further comprising setting remaining input data to zero.
14. The method of claim 8 , further comprising processing a decimation in frequency FFT operation.
15. The method of claim 8 , further comprising buffering input data and output data.
16. The method of claim 8 , further comprising decoding radio frequency channel data from the transformed data.