X-Git-Url: https://git.stderr.nl/gitweb?a=blobdiff_plain;f=FFT_support.cpp;h=7fc2484be97043c091505e99354a165015e2e2a1;hb=00b2c5a7eced88e39b762255d361d61f78e2abe3;hp=23d07f08ca102e114e7428807701f364fcdcc566;hpb=a62dbd706365d44bdcac9f8ac4c7c6dd05484642;p=matthijs%2Fprojects%2Fmontium-fft.git

diff --git a/FFT_support.cpp b/FFT_support.cpp
index 23d07f0..7fc2484 100644
--- a/FFT_support.cpp
+++ b/FFT_support.cpp
@@ -2,12 +2,11 @@
 #include <cstdio>
 #include <cmath>
 
-
-/* Didn't the Montium use Q15 instead of Q14? */
+/* Use Q15 fixed point format (1 sign bit plus 15 fractional bits) */
 #define FIXED_POINT 15
 #define WORD_SIZE   16
 
-#define WORDS_PER_LINE 4
+#define WORDS_PER_LINE 8
 #define WORDS_PER_GROUP 1
 
 mem input_a_re, input_a_im, input_b_re, input_b_im, output_a_re, output_a_im, output_b_re, output_b_im, twiddle_re, twiddle_im; 
@@ -68,7 +67,9 @@ void pre_run()
 	
 	for (i=0;i<PARAM_N_t;i++)
 	{
-		int value = to_fixed(sin((float)i*2*M_PI/PARAM_N_t));
+		/* We take the sine from 0 to 2*2*Pi, ie two periods. We divide 
+		 * the value by PARAM_N_t to prevent overflow. */
+		int value = to_fixed(sin((float)i*2*2*M_PI/PARAM_N_t)/PARAM_N_t);
 
 		if (i<PARAM_N_t/2)
 		{
@@ -100,12 +101,20 @@ void pre_run()
 	print_mem(input_a_re, 0, PARAM_N_t/2, true);
 	printf("re(in_b)\n");
 	print_mem(input_b_re, 0, PARAM_N_t/2, true);
+	
+/* Write out memory contents for use by the python simulator */
+	save_mem_range_to_file(input_a_re->id, 0, PARAM_N_t/2, "Memory/sin_a_re.mm");
+	save_mem_range_to_file(input_a_im->id, 0, PARAM_N_t/2, "Memory/sin_a_im.mm");
+	save_mem_range_to_file(input_b_re->id, 0, PARAM_N_t/2, "Memory/sin_b_re.mm");
+	save_mem_range_to_file(input_b_im->id, 0, PARAM_N_t/2, "Memory/sin_b_im.mm");
+	save_mem_range_to_file(twiddle_re->id, 0, PARAM_N_t/2, "Memory/twiddle_re.mm");
+	save_mem_range_to_file(twiddle_im->id, 0, PARAM_N_t/2, "Memory/twiddle_im.mm");
 }
 
 void post_run()
 {
 	if (PARAM_n_t % 2 == 0) {
-		/* When the number of stages is odd, the 
+		/* When the number of stages is even, the 
 		 * outputs end up at the left memories again */
 		output_a_re  = alloc_mem(P0M0);
 		output_a_im  = alloc_mem(P1M0);
@@ -117,11 +126,18 @@ void post_run()
 		output_b_re  = alloc_mem(P2M1);
 		output_b_im  = alloc_mem(P3M1);
 	}
-	printf("re(out_a)\n");
+	printf("re(out)\n");
 	print_mem(output_a_re, 0, PARAM_N_t/2, true);
 	print_mem(output_b_re, 0, PARAM_N_t/2, true);
-	printf("im(out_a)\n");
+	printf("im(out)\n");
 	print_mem(output_a_im, 0, PARAM_N_t/2, true);
 	print_mem(output_b_im, 0, PARAM_N_t/2, true);
+	
+	printf("re(out)\n");
+	print_mem(output_a_re, 0, PARAM_N_t/2, false);
+	print_mem(output_b_re, 0, PARAM_N_t/2, false);
+	printf("im(out)\n");
+	print_mem(output_a_im, 0, PARAM_N_t/2, false);
+	print_mem(output_b_im, 0, PARAM_N_t/2, false);
 
 }