14.1. FFT Performance Test Example
14.1.1. Overview
This example demonstrates the performance comparison of different FFT implementations in HPM SDK. The example tests the execution time and accuracy of various FFT algorithms, including DSP radix-4, DSP radix-2, Q31 DSP radix-2, and Q31 FFA FFT (if supported).
14.1.2. Features
Generate composite signal with three sine waves
Test performance of different FFT implementations: - DSP radix-4 complex FFT - DSP radix-2 complex FFT - Q31 DSP radix-2 complex FFT - Q31 FFA FFT (if supported)
Verify FFT and IFFT accuracy
Test performance with different points (64-1024 points)
14.1.3. Hardware Requirements
Test FFA performance on SOC that support FFA (e.g. HPM63xx, HPM6Exx, HPM68xx, HPM6Pxx)
14.1.4. Software Requirements
HPM SDK
CMake 3.20.0 or higher
Cross-compilation toolchain
14.1.5. Build Instructions
Enter the example directory
Create and enter build directory
Run CMake configuration
Build the project
14.1.6. Run Instructions
Flash the compiled binary to the development board
View output through serial port
Observe performance data of different FFT implementations
14.1.7. Output Description
The program will output the following information: - CPU frequency - Execution time of different FFT implementations - Amplitude of frequency components - Accuracy verification results
14.1.8. Notes
Ensure proper power supply to the development board
Ensure correct serial port connection
Observe LED status to confirm program running state
Different development boards may support different FFT implementations
14.1.9. Programming
The software generates several sine waves with different amplitudes and phases and superimposes them to generate a waveform. The ifft data and the fft transform data are compared to see if the ifft data and the fft transform data are the same. The sine wave is shown below:
Amplitude 11, frequency 8
Amplitude 19, frequency 17
Amplitude 13, frequency 24
14.1.10. Performance Optimization
segger turns on O3 optimization by default
hpm_math is by default optimized for CPU Cooley-Tukey algorithm calculations, which increases space usage
To reproduce the test results shown in this documentation, compile with -DHPM_BUILD_TYPE=ram. This ensures DSP computational routines are placed in tightly coupled memory for optimal performance. Example build command:
cmake -GNinja -DBOARD=hpm6750evkmini -DHPM_BUILD_TYPE=ram ..
14.1.11. Running the example
The serial terminal outputs the name of the calculation, the number of samples, and the data of the amplitude and frequency characteristics, as well as the running time of each unit, and outputs PASS or ERROR NUM at the end.
The serial port output is shown below:
dsp fft radix-4 Total samples: 64.
total times:5813 tick.
------------------------------------
DC component amplitude:10.000006.
Frequency:8.000000, Amplitude:11.000008.
Frequency:17.000000, Amplitude:18.999988.
Frequency:24.000000, Amplitude:23.000000.
------------------------------------
dsp ifft radix-4 Total samples: 64.
total times:5961 tick.
------------------------------------
dsp fft radix-4 Total samples: 256.
total times:29671 tick.
------------------------------------
DC component amplitude:9.999996.
Frequency:8.000000, Amplitude:11.000002.
Frequency:17.000000, Amplitude:18.999998.
Frequency:24.000000, Amplitude:23.000003.
------------------------------------
dsp ifft radix-4 Total samples: 256.
total times:30220 tick.
------------------------------------
dsp fft radix-4 Total samples: 1024.
total times:144992 tick.
------------------------------------
DC component amplitude:9.999997.
Frequency:8.000000, Amplitude:11.000000.
Frequency:17.000000, Amplitude:19.000000.
Frequency:24.000000, Amplitude:23.000000.
------------------------------------
dsp ifft radix-4 Total samples: 1024.
total times:147161 tick.
------------------------------------
**************************************
dsp fft radix-2 Total samples: 64.
total times:9280 tick.
------------------------------------
DC component amplitude:10.000006.
Frequency:8.000000, Amplitude:11.000008.
Frequency:17.000000, Amplitude:18.999988.
Frequency:24.000000, Amplitude:23.000000.
------------------------------------
dsp ifft radix-2 Total samples: 64.
total times:9544 tick.
------------------------------------
dsp fft radix-2 Total samples: 128.
total times:21119 tick.
------------------------------------
DC component amplitude:9.999998.
Frequency:8.000000, Amplitude:11.000001.
Frequency:17.000000, Amplitude:18.999996.
Frequency:24.000000, Amplitude:23.000003.
------------------------------------
dsp ifft radix-2 Total samples: 128.
total times:21575 tick.
------------------------------------
dsp fft radix-2 Total samples: 256.
total times:47643 tick.
------------------------------------
DC component amplitude:9.999996.
Frequency:8.000000, Amplitude:11.000002.
Frequency:17.000000, Amplitude:19.000000.
Frequency:24.000000, Amplitude:23.000003.
------------------------------------
dsp ifft radix-2 Total samples: 256.
total times:48582 tick.
------------------------------------
dsp fft radix-2 Total samples: 512.
total times:106047 tick.
------------------------------------
DC component amplitude:9.999997.
Frequency:8.000000, Amplitude:11.000000.
Frequency:17.000000, Amplitude:19.000000.
Frequency:24.000000, Amplitude:22.999998.
------------------------------------
dsp ifft radix-2 Total samples: 512.
total times:108005 tick.
------------------------------------
dsp fft radix-2 Total samples: 1024.
total times:234172 tick.
------------------------------------
DC component amplitude:9.999997.
Frequency:8.000000, Amplitude:11.000000.
Frequency:17.000000, Amplitude:19.000000.
Frequency:24.000000, Amplitude:23.000000.
------------------------------------
dsp ifft radix-2 Total samples: 1024.
total times:237975 tick.
------------------------------------
**************************************
dsp fft q31 radix-2 Total samples: 64.
total times:3782 tick.
------------------------------------
DC component amplitude:10.000006.
Frequency:8.000000, Amplitude:11.000009.
Frequency:17.000000, Amplitude:18.999988.
Frequency:24.000000, Amplitude:23.000000.
------------------------------------
dsp ifft q31 radix-2 Total samples: 64.
total times:4220 tick.
------------------------------------
dsp fft q31 radix-2 Total samples: 128.
total times:8252 tick.
------------------------------------
DC component amplitude:9.999998.
Frequency:8.000000, Amplitude:11.000002.
Frequency:17.000000, Amplitude:18.999996.
Frequency:24.000000, Amplitude:23.000003.
------------------------------------
dsp ifft q31 radix-2 Total samples: 128.
total times:9274 tick.
------------------------------------
dsp fft q31 radix-2 Total samples: 256.
total times:17995 tick.
------------------------------------
DC component amplitude:9.999995.
Frequency:8.000000, Amplitude:11.000002.
Frequency:17.000000, Amplitude:19.000000.
Frequency:24.000000, Amplitude:23.000005.
------------------------------------
dsp ifft q31 radix-2 Total samples: 256.
total times:20619 tick.
------------------------------------
dsp fft q31 radix-2 Total samples: 512.
total times:39039 tick.
------------------------------------
DC component amplitude:9.999995.
Frequency:8.000000, Amplitude:11.000001.
Frequency:17.000000, Amplitude:19.000000.
Frequency:24.000000, Amplitude:23.000000.
------------------------------------
dsp ifft q31 radix-2 Total samples: 512.
total times:45407 tick.
------------------------------------
dsp fft q31 radix-2 Total samples: 1024.
total times:85195 tick.
------------------------------------
DC component amplitude:9.999995.
Frequency:8.000000, Amplitude:11.000002.
Frequency:17.000000, Amplitude:19.000003.
Frequency:24.000000, Amplitude:23.000001.
------------------------------------
dsp ifft q31 radix-2 Total samples: 1024.
total times:99603 tick.
------------------------------------
**************************************
Software fft cooley tukey Total samples: 64.
total times:14493 tick.
------------------------------------
DC component amplitude:10.000006.
Frequency:8.000000, Amplitude:11.000014.
Frequency:17.000000, Amplitude:18.999998.
Frequency:24.000000, Amplitude:23.000019.
------------------------------------
Software fft cooley tukey Total samples: 128.
total times:29009 tick.
------------------------------------
DC component amplitude:9.999998.
Frequency:8.000000, Amplitude:11.000004.
Frequency:17.000000, Amplitude:19.000003.
Frequency:24.000000, Amplitude:23.000015.
------------------------------------
Software fft cooley tukey Total samples: 256.
total times:61116 tick.
------------------------------------
DC component amplitude:9.999996.
Frequency:8.000000, Amplitude:11.000000.
Frequency:17.000000, Amplitude:18.999998.
Frequency:24.000000, Amplitude:23.000000.
------------------------------------
Software fft cooley tukey Total samples: 512.
total times:131520 tick.
------------------------------------
DC component amplitude:9.999997.
Frequency:8.000000, Amplitude:10.999999.
Frequency:17.000000, Amplitude:19.000001.
Frequency:24.000000, Amplitude:23.000000.
------------------------------------
Software fft cooley tukey Total samples: 1024.
total times:285106 tick.
------------------------------------
DC component amplitude:9.999997.
Frequency:8.000000, Amplitude:10.999997.
Frequency:17.000000, Amplitude:19.000000.
Frequency:24.000000, Amplitude:22.999996.
------------------------------------
**************************************
------------------------------------
convert data from float to q31, nums:128.
total times:3163 tick.
convert data from q31 to float, nums:128.
total times:1177 tick.
------------------------------------
------------------------------------
convert data from float to q31, nums:256.
total times:6225 tick.
convert data from q31 to float, nums:256.
total times:2325 tick.
------------------------------------
------------------------------------
convert data from float to q31, nums:512.
total times:12269 tick.
convert data from q31 to float, nums:512.
total times:4629 tick.
------------------------------------
------------------------------------
convert data from float to q31, nums:1024.
total times:24395 tick.
convert data from q31 to float, nums:1024.
total times:9237 tick.
------------------------------------
------------------------------------
convert data from float to q31, nums:2048.
total times:47949 tick.
convert data from q31 to float, nums:2048.
total times:18453 tick.
------------------------------------
PASS.
The performance is shown in the following table:
Samples |
64 |
128 |
256 |
512 |
1024 |
|---|---|---|---|---|---|
DSP radix-4 |
5900 |
N |
29869 |
N |
145366 |
DSP radix-2 |
9345 |
21220 |
47762 |
106211 |
234534 |
DSP radix-2(Q31) |
4378 |
9581 |
21177 |
46126 |
101331 |
FFAQ31 |
2729 |
4923 |
7769 |
18999 |
N |
CPU(Cooley-Tukey) |
14495 |
29171 |
61176 |
131084 |
283441 |
DSP radix-4 |
6016 |
N |
30384 |
N |
147651 |
DSP radix-2 |
9558 |
21632 |
48733 |
108296 |
238775 |
DSP radix-2(Q31) |
4641 |
10301 |
22980 |
50645 |
111359 |
FFAQ31 |
2687 |
4898 |
9152 |
18956 |
N |
Q31 to Float |
1208 |
2392 |
4757 |
9493 |
18965 |
Float to Q31 |
5517 |
10958 |
21970 |
44022 |
88055 |