diff --git a/fpga/hls/parallel_stream.h b/fpga/hls/parallel_stream.h
index ac50b37b..10976f9f 100644
--- a/fpga/hls/parallel_stream.h
+++ b/fpga/hls/parallel_stream.h
@@ -10,7 +10,7 @@
 #include <chrono>
 
 namespace hls {
-    template<class T> class stream {
+    template<class T, int DEPTH=0> class stream {
     private:
         mutable std::mutex m;
         std::condition_variable c_empty;
diff --git a/fpga/hls/spot_finder.cpp b/fpga/hls/spot_finder.cpp
index b69c994d..848c4255 100644
--- a/fpga/hls/spot_finder.cpp
+++ b/fpga/hls/spot_finder.cpp
@@ -358,6 +358,31 @@ void spot_finder_2(STREAM_512 &data_in,
     hls::stream<ap_uint<SUM_BITWIDTH*32>> sum_stream_0, sum_stream_1, sum_stream_2;
     hls::stream<ap_uint<SUM2_BITWIDTH*32>> sum2_stream_0, sum2_stream_1, sum2_stream_2;
     hls::stream<ap_uint<MASK_SUM_BITWIDTH*32>> valid_stream_0, valid_stream_1, valid_stream_2;
+#pragma HLS STREAM variable=data_stream_0 depth=512 type=fifo
+#pragma HLS bind_storage variable=data_stream_0 type=fifo impl=bram
+#pragma HLS STREAM variable=data_stream_1 depth=64 type=fifo
+#pragma HLS bind_storage variable=data_stream_1 type=fifo impl=bram
+#pragma HLS STREAM variable=data_stream_2 depth=64 type=fifo
+#pragma HLS bind_storage variable=data_stream_2 type=fifo impl=bram
+
+#pragma HLS STREAM variable=sum_stream_0 depth=512 type=fifo
+#pragma HLS bind_storage variable=sum_stream_0 type=fifo impl=bram
+#pragma HLS STREAM variable=sum_stream_1 depth=64 type=fifo
+#pragma HLS bind_storage variable=sum_stream_1 type=fifo impl=bram
+#pragma HLS STREAM variable=sum_stream_2 depth=64 type=fifo
+#pragma HLS bind_storage variable=sum_stream_2 type=fifo impl=bram
+#pragma HLS STREAM variable=sum2_stream_0 depth=512 type=fifo
+#pragma HLS bind_storage variable=sum2_stream_0 type=fifo impl=bram
+#pragma HLS STREAM variable=sum2_stream_1 depth=64 type=fifo
+#pragma HLS bind_storage variable=sum2_stream_1 type=fifo impl=bram
+#pragma HLS STREAM variable=sum2_stream_2 depth=64 type=fifo
+#pragma HLS bind_storage variable=sum2_stream_2 type=fifo impl=bram
+#pragma HLS STREAM variable=valid_stream_0 depth=512 type=fifo
+#pragma HLS bind_storage variable=valid_stream_0 type=fifo impl=bram
+#pragma HLS STREAM variable=valid_stream_1 depth=64 type=fifo
+#pragma HLS bind_storage variable=valid_stream_1 type=fifo impl=bram
+#pragma HLS STREAM variable=valid_stream_2 depth=64 type=fifo
+#pragma HLS bind_storage variable=valid_stream_2 type=fifo impl=bram
 
 #ifdef __SYNTHESIS__
     spot_finder_col_sum(data_in, data_stream_0, sum_stream_0, sum2_stream_0, valid_stream_0);
diff --git a/fpga/hls/spot_finder.h b/fpga/hls/spot_finder.h
index d5b001f8..b9bfff4d 100644
--- a/fpga/hls/spot_finder.h
+++ b/fpga/hls/spot_finder.h
@@ -48,10 +48,16 @@ ap_uint<N*32> prefix_sum(const ap_uint<N*(32+(2 * FPGA_NBX))> ext_column_sum) {
         tmp_sum += column_sum[i];
     }
 
+    //for (int i = 0; i < 32; i++) {
+    //    tmp_sum += column_sum[i + 2 * FPGA_NBX];
+    //    line_sum[i] = tmp_sum;
+    //    tmp_sum -= column_sum[i];
+    //}
+
     for (int i = 0; i < 32; i++) {
-        tmp_sum += column_sum[i + 2 * FPGA_NBX];
-        line_sum[i] = tmp_sum;
-        tmp_sum -= column_sum[i];
+        line_sum[i] = 0;
+        for (int j = 0; j < 2 * FPGA_NBX + 1; j++)
+            line_sum[i] += column_sum[i + j];
     }
 
     return pack32(line_sum);