200 lines
6.9 KiB
C
200 lines
6.9 KiB
C
#include <stdio.h>
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#include <string.h>
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#include <stdbool.h>
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#include <math.h>
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#include <stdint.h>
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#include <common_func.h>
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#include <confreg_time.h>
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#include <dma.h>
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#include <fft.h>
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#include "../fft_test_data.h"
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// BSP板级支持包所需全局变量
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unsigned long UART_BASE = 0xbf000000;
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unsigned long CONFREG_TIMER_BASE = 0xbf20f100;
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unsigned long CONFREG_CLOCKS_PER_SEC = 50000000L;
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unsigned long CORE_CLOCKS_PER_SEC = 33000000L;
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const float PI = 3.14159265358979323846;
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#define FFT_MAX_ABS_ERROR_LIMIT 8
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// 软件FFT实现 (基2 DIT-FFT 算法)
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void sw_fft(float re[], float im[], int n) {
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int i, j, k, l;
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float tr, ti, ur, ui, wr, wi;
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j = 0;
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for (i = 0; i < n - 1; i++) {
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if (i < j) {
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tr = re[i]; ti = im[i];
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re[i] = re[j]; im[i] = im[j];
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re[j] = tr; im[j] = ti;
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}
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k = n / 2;
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while (k <= j) {
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j -= k;
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k /= 2;
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}
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j += k;
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}
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for (l = 1; l < n; l *= 2) {
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ur = 1.0;
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ui = 0.0;
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wr = cos(PI / l);
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wi = -sin(PI / l);
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for (i = 0; i < n; i += 2 * l) {
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ur = 1.0;
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ui = 0.0;
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for (j = 0; j < l; j++) {
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int p = i + j;
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int q = p + l;
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tr = re[q] * ur - im[q] * ui;
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ti = re[q] * ui + im[q] * ur;
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re[q] = re[p] - tr;
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im[q] = im[p] - ti;
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re[p] += tr;
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im[p] += ti;
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float next_ur = ur * wr - ui * wi;
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ui = ur * wi + ui * wr;
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ur = next_ur;
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}
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}
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}
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}
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// 全局对齐数组：作为 DMA 的源和目的内存。
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// FFT 外设仍按 32-bit AXI word 编址，每个 word 的低 16 bit 作为一个 signed 样本。
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int32_t hw_in_re_arr[FFT_POINT_NUM] __attribute__((aligned(64)));
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int32_t hw_in_im_arr[FFT_POINT_NUM] __attribute__((aligned(64)));
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int32_t hw_out_re_arr[FFT_POINT_NUM] __attribute__((aligned(64)));
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int32_t hw_out_im_arr[FFT_POINT_NUM] __attribute__((aligned(64)));
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int main(int argc, char** argv)
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{
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unsigned int fft_csr = RegRead(FFT_CSR_REG);
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printf("fft_csr init = %x\n", fft_csr);
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// 获取外设的纯物理地址 (屏蔽高3位 0x1FFFFFFF)
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uint32_t phys_fft_in_re = FFT_IN_RE_BASE & 0x1FFFFFFF;
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uint32_t phys_fft_in_im = FFT_IN_IM_BASE & 0x1FFFFFFF;
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uint32_t phys_fft_out_re = FFT_OUT_RE_BASE & 0x1FFFFFFF;
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uint32_t phys_fft_out_im = FFT_OUT_IM_BASE & 0x1FFFFFFF;
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// 获取内存数组的纯物理地址，并包装为 CPU 使用的无缓存(Uncached)指针
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volatile int32_t *uncached_in_re = (volatile int32_t *)(((uint32_t)hw_in_re_arr & 0x1FFFFFFF) | 0xA0000000);
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volatile int32_t *uncached_in_im = (volatile int32_t *)(((uint32_t)hw_in_im_arr & 0x1FFFFFFF) | 0xA0000000);
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volatile int32_t *uncached_out_re = (volatile int32_t *)(((uint32_t)hw_out_re_arr & 0x1FFFFFFF) | 0xA0000000);
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volatile int32_t *uncached_out_im = (volatile int32_t *)(((uint32_t)hw_out_im_arr & 0x1FFFFFFF) | 0xA0000000);
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// 准备软件 FFT 测试数据
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float sw_in_re[FFT_POINT_NUM];
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float sw_in_im[FFT_POINT_NUM];
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for (int i = 0; i < FFT_POINT_NUM; i++) {
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int16_t sample = (int16_t)fft_test_sample((unsigned int)i);
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sw_in_re[i] = (float)sample;
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sw_in_im[i] = 0.0f;
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// 硬件输入为 16-bit signed，写入 32-bit word 的低半字。
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uncached_in_re[i] = (int32_t)sample;
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uncached_in_im[i] = 0;
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// 清理输出内存以防干扰
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uncached_out_re[i] = 0xDEADBEEF;
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uncached_out_im[i] = 0xDEADBEEF;
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}
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unsigned int tick_start, tick_end;
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unsigned int hw_time, sw_time;
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// 硬件加速 FFT 测试 (纯 DMA 搬运)
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printf("\n--- Starting Hardware FFT with DMA ---\n");
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tick_start = get_ns(); // 开始计时
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uint32_t transfer_bytes = FFT_POINT_NUM * 4; // 1024个点 * 4字节，低16位有效
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// MA 将数据从内存搬运到 FFT 输入外设
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dma_start_transfer(0, ((uint32_t)hw_in_re_arr & 0x1FFFFFFF), phys_fft_in_re, transfer_bytes, 100);
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dma_start_transfer(1, ((uint32_t)hw_in_im_arr & 0x1FFFFFFF), phys_fft_in_im, transfer_bytes, 200);
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dma_wait_polling(0);
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dma_wait_polling(1);
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// 启动 FFT 并等待计算完成
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fft_start();
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fft_wait();
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// DMA 将结果从 FFT 输出外设搬回内存
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dma_start_transfer(0, phys_fft_out_re, ((uint32_t)hw_out_re_arr & 0x1FFFFFFF), transfer_bytes, 10);
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dma_start_transfer(1, phys_fft_out_im, ((uint32_t)hw_out_im_arr & 0x1FFFFFFF), transfer_bytes, 20);
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dma_wait_polling(0);
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dma_wait_polling(1);
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tick_end = get_ns(); // 结束计时
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hw_time = tick_end - tick_start;
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// 纯软件 FFT 测试
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printf("--- Starting Software FFT ---\n");
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tick_start = get_ns();
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sw_fft(sw_in_re, sw_in_im, FFT_POINT_NUM);
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tick_end = get_ns();
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sw_time = tick_end - tick_start;
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// 打印对比结果
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printf("\n--- Performance Comparison ---\n");
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printf("Timer Clock Freq : %lu Hz\n", CONFREG_CLOCKS_PER_SEC);
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printf("Hardware FFT Time: %u ns (%.3f ms)\n", hw_time, (float)hw_time / 1000000.0);
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printf("Software FFT Time: %u ns (%.3f ms)\n", sw_time, (float)sw_time / 1000000.0);
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if (hw_time > 0) {
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printf("Speedup Ratio : %.2fx\n", (float)sw_time / hw_time);
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}
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printf("\n--- Verification (%d-bit FFT, only showing bins with energy > 10) ---\n", FFT_SAMPLE_BITS);
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int max_abs_err_re = 0;
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int max_abs_err_im = 0;
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for (int i = 0; i < FFT_POINT_NUM; i++) {
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// CPU 通过无缓存指针读取 DMA 搬运回来的结果
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int32_t hw_re = uncached_out_re[i];
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int32_t hw_im = uncached_out_im[i];
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int32_t sw_re = (int32_t)sw_in_re[i] / FFT_POINT_NUM;
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int32_t sw_im = (int32_t)sw_in_im[i] / FFT_POINT_NUM;
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int err_re = (int)(hw_re - sw_re);
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int err_im = (int)(hw_im - sw_im);
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if (err_re < 0) err_re = -err_re;
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if (err_im < 0) err_im = -err_im;
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if (err_re > max_abs_err_re) max_abs_err_re = err_re;
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if (err_im > max_abs_err_im) max_abs_err_im = err_im;
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if (fabs((float)hw_re) > 10 || fabs((float)hw_im) > 10) {
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printf("Bin [%4d] Hz: HW(Re:%6d, Im:%6d) | SW(Re:%6d, Im:%6d)\n",
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i,
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hw_re, hw_im,
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sw_re, sw_im);
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}
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}
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printf("Max Abs Error : Re=%d, Im=%d\n", max_abs_err_re, max_abs_err_im);
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int passed = max_abs_err_re <= FFT_MAX_ABS_ERROR_LIMIT &&
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max_abs_err_im <= FFT_MAX_ABS_ERROR_LIMIT;
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printf("FFT_DMA_MAX_ABS_ERROR_RE=%d\n", max_abs_err_re);
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printf("FFT_DMA_MAX_ABS_ERROR_IM=%d\n", max_abs_err_im);
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printf("FFT_DMA_ERROR_LIMIT=%d\n", FFT_MAX_ABS_ERROR_LIMIT);
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printf("FFT_DMA_RESULT=%s\n", passed ? "PASS" : "FAIL");
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printf("FFT_DMA_DONE\n");
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return passed ? 0 : 1;
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}
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