.. _fft_performance_test: FFT 性能测试示例 ================ 概述 ---- 本示例演示了 HPM SDK 中不同 FFT 实现方式的性能对比。示例测试了多种 FFT 算法的执行时间和精度，包括 DSP radix-4、DSP radix-2、Q31 DSP radix-2 以及 Q31 FFA FFT（如果支持）。 功能说明 -------- - 生成包含三个正弦波的合成信号 - 测试不同 FFT 实现方式的性能： - DSP radix-4 复数 FFT - DSP radix-2 复数 FFT - Q31 DSP radix-2 复数 FFT - Q31 FFA FFT（如果支持） - 验证 FFT 和 IFFT 的精度 - 测试不同点数（64-1024点）的性能 硬件要求 -------- - 测试FFA性能需要支持 FFA 功能的SOC（如 HPM63xx、HPM6Exx、HPM68xx、HPM6Pxx） 软件要求 -------- - HPM SDK - CMake 3.20.0 或更高版本 - 交叉编译工具链 构建说明 -------- 1. 进入示例目录 2. 创建构建目录并进入 3. 运行 CMake 配置 4. 编译项目 运行说明 -------- 1. 将编译生成的二进制文件烧录到开发板 2. 通过串口查看输出结果 3. 观察不同 FFT 实现方式的性能数据 输出说明 -------- 程序会输出以下信息： - CPU 频率 - 不同 FFT 实现方式的执行时间 - 频率分量的幅度 - 精度验证结果 注意事项 -------- - 确保开发板供电正常 - 确保串口连接正确 - 观察 LED 状态以确认程序运行状态 - 不同开发板支持的 FFT 实现方式可能不同 程序设计 ------------ 软件生成生成几个幅值和相位不同的正弦波并叠加生成一个波形，然后使用fft变换求出幅频特性数据，最后做ifft回复原始数据， 并比对ifft的数据和fft变换的数据是否相一致。几个正弦波如下所示: - 幅值11，频率8 - 幅值19，频率17 - 幅值13，频率24 硬件设置 ------------ 无特殊设置 性能优化 ------------ - segger已经默认开启O3优化 - hpm_math默认开启了对CPU Cooley-Tukey算法的计算优化，会增加空间占用 - 复现本文档测试结果需要使用-DHPM_BUILD_TYPE=ram进行编译，这样可以确保DSP计算例程放置在紧耦合内存中以获得最佳性能。构建命令示例： .. code-block:: shell cmake -GNinja -DBOARD=hpm6750evkmini -DHPM_BUILD_TYPE=ram .. 运行现象 ------------ 当工程正确运行后，串口终端会输出计算的名称，采样点数，以及幅频特性的数据，以及每一个单元的运行时间，并在最后输出PASS或者ERROR NUM. 串口输出如下所示： .. code-block:: console 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. 性能如下表所示： .. list-table:: :header-rows: 1 * - 采样点 - 64 - 128 - 256 - 512 - 1024 * - DSP radix-4（fpu） - 5900 - N - 29869 - N - 145366 * - DSP radix-2（fpu） - 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（fpu） - 6016 - N - 30384 - N - 147651 * - DSP radix-2（fpu） - 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