Optimize FFT test input generation

sdk/software/examples/fft_dma/main.c

@@ -8,6 +8,7 @@
 #include <confreg_time.h>
 #include <dma.h>
 #include <fft.h>
+#include "../fft_test_data.h"
 
 // BSP板级支持包所需全局变量
 unsigned long UART_BASE = 0xbf000000;
@@ -93,18 +94,14 @@ int main(int argc, char** argv)
     float sw_in_re[FFT_POINT_NUM];
     float sw_in_im[FFT_POINT_NUM];
 
-    // 初始化测试波形
     for (int i = 0; i < FFT_POINT_NUM; i++) {
-        float dc_part   = 4000.0f;
-        float f10_part  = 8000.0f * cos(2 * PI * 10.0 * i / FFT_POINT_NUM);
-        float f200_part = 6000.0f * sin(2 * PI * 200.0 * i / FFT_POINT_NUM);
-        float f400_part = 3000.0f * sin(2 * PI * 400.0 * i / FFT_POINT_NUM);
-        
-        sw_in_re[i] = dc_part + f10_part + f200_part + f400_part;
+        int32_t sample = fft_test_sample((unsigned int)i);
+
+        sw_in_re[i] = (float)sample;
         sw_in_im[i] = 0.0f;
 
         // 硬件输入需要转为整数存入无缓存内存
-        uncached_in_re[i]  = (int32_t)sw_in_re[i];
+        uncached_in_re[i]  = sample;
         uncached_in_im[i]  = 0;
         
         // 清理输出内存以防干扰
@@ -176,4 +173,4 @@ int main(int argc, char** argv)
     }
 
     return 0;
-}
+}