Try not lost data on dsp (Less noise on small signals)

Use int64_t acc for values
Use double on calculation

Not cache freq on si5351_set_frequency_with_offset (to fast change in rare cases on cw mode, and process wrong DSP block) as i write before need change DSP delay tactic

dsp.c

@@ -41,48 +41,57 @@ const int16_t sincos_tbl[48][2] = {
   {-24636, -21605 }, {-32698,  -2143 }, {-27246,  18205 }, {-10533,  31029 }
 };
 
-int32_t acc_samp_s;
-int32_t acc_samp_c;
-int32_t acc_ref_s;
-int32_t acc_ref_c;
+int64_t acc_samp_s;
+int64_t acc_samp_c;
+int64_t acc_ref_s;
+int64_t acc_ref_c;
 
 void
 dsp_process(int16_t *capture, size_t length)
 {
-  uint32_t *p = (uint32_t*)capture;
-  uint32_t len = length / 2;
   uint32_t i;
-  int32_t samp_s = 0;
-  int32_t samp_c = 0;
-  int32_t ref_s = 0;
-  int32_t ref_c = 0;
-
-  for (i = 0; i < len; i++) {
-    uint32_t sr = *p++;
-    int16_t ref = sr & 0xffff;
-    int16_t smp = (sr>>16) & 0xffff;
+#if 1
+  acc_samp_s = 0;
+  acc_samp_c = 0;
+  acc_ref_s = 0;
+  acc_ref_c = 0;
+  for (i = 0; i < length; i+=2) {
+    int32_t ref = capture[i+0];
+    int32_t smp = capture[i+1];
 #ifdef ENABLED_DUMP
     ref_buf[i] = ref;
     samp_buf[i] = smp;
 #endif
-    int32_t s = sincos_tbl[i][0];
-    int32_t c = sincos_tbl[i][1];
-    samp_s += smp * s / 16;
-    samp_c += smp * c / 16;
-    ref_s += ref * s / 16;
-    ref_c += ref * c / 16;
-#if 0
-    uint32_t sc = *(uint32_t)&sincos_tbl[i];
-    samp_s = __SMLABB(sr, sc, samp_s);
-    samp_c = __SMLABT(sr, sc, samp_c);
-    ref_s = __SMLATB(sr, sc, ref_s);
-    ref_c = __SMLATT(sr, sc, ref_c);
-#endif
+    int32_t s = ((int16_t *)sincos_tbl)[i+0];
+    int32_t c = ((int16_t *)sincos_tbl)[i+1];
+    acc_samp_s += (smp * s);
+    acc_samp_c += (smp * c);
+    acc_ref_s  += (ref * s);
+    acc_ref_c  += (ref * c);
+  }
+#else
+  uint32_t len = length / 2;
+  int64_t samp_s = 0;
+  int64_t samp_c = 0;
+  int64_t ref_s = 0;
+  int64_t ref_c = 0;
+  //        HI  LO
+  int32_t *cos_sin = (int32_t *)sincos_tbl;
+  int32_t *ref_smp = (int32_t *)capture;
+  for (i = 0; i < len; i++) {
+    //
+    samp_s = __SMLALBB(*ref_smp, *cos_sin, samp_s); // samp_s+= smp * sin
+    samp_c = __SMLALBT(*ref_smp, *cos_sin, samp_c); // samp_c+= smp * cos
+    ref_s  = __SMLALTB(*ref_smp, *cos_sin, ref_s);  // ref_s += ref * sin
+    ref_c  = __SMLALTT(*ref_smp, *cos_sin, ref_c);  // ref_s += ref * cos
+    ref_smp++;
+    cos_sin++;
   }
   acc_samp_s = samp_s;
   acc_samp_c = samp_c;
-  acc_ref_s = ref_s;
-  acc_ref_c = ref_c;
+  acc_ref_s  = ref_s;
+  acc_ref_c  = ref_c;
+#endif
 }
 
 void
@@ -90,12 +99,12 @@ calculate_gamma(float gamma[2])
 {
 #if 1
   // calculate reflection coeff. by samp divide by ref
-  float rs = acc_ref_s;
-  float rc = acc_ref_c;
-  float rr = rs * rs + rc * rc;
+  double rs = acc_ref_s;
+  double rc = acc_ref_c;
+  double rr = rs * rs + rc * rc;
   //rr = sqrtf(rr) * 1e8;
-  float ss = acc_samp_s;
-  float sc = acc_samp_c;
+  double ss = acc_samp_s;
+  double sc = acc_samp_c;
   gamma[0] =  (sc * rc + ss * rs) / rr;
   gamma[1] =  (ss * rc - sc * rs) / rr;
 #elif 0

si5351.c

@@ -354,13 +354,13 @@ int
 si5351_set_frequency_with_offset(uint32_t freq, int offset, uint8_t drive_strength){
   uint8_t band;
   int delay = DELAY_NORMAL;
-  if (freq == current_freq)
-    return delay;
+//  if (freq == current_freq)
+//    return delay;
   uint32_t ofreq = freq + offset;
   uint32_t mul = 1, omul = 1;
   uint32_t rdiv = SI5351_R_DIV_1;
   uint32_t fdiv;
-  current_freq = freq;
+//  current_freq = freq;
   if (freq >= config.harmonic_freq_threshold * 7U) {
      mul =  9;
     omul = 11;