Corrected issue #106

Energy saturation in fixed point for lms norm
ARM-software · Jun 14, 2023 · 540161c · 540161c
1 parent 8703d45
commit 540161c
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Showing 2 changed files with 4 additions and 2 deletions.
diff --git a/Source/FilteringFunctions/arm_lms_norm_q15.c b/Source/FilteringFunctions/arm_lms_norm_q15.c
@@ -116,6 +116,7 @@ void arm_lms_norm_q15(
     /* Update the energy calculation */
     energy -= (((q31_t) x0 * (x0)) >> 15);
     energy += (((q31_t) in * (in)) >> 15);
+    energy = (q15_t) __SSAT(energy, 16);
 
     /* Set the accumulator to zero */
     acc = 0;

diff --git a/Source/FilteringFunctions/arm_lms_norm_q31.c b/Source/FilteringFunctions/arm_lms_norm_q31.c
@@ -115,8 +115,9 @@ void arm_lms_norm_q31(
 
     /* Update the energy calculation */
     energy = (q31_t) ((((q63_t) energy << 32) - (((q63_t) x0 * x0) << 1)) >> 32);
-    energy = (q31_t) (((((q63_t) in * in) << 1) + (energy << 32)) >> 32);
-
+    energy = ((((q63_t) in * in) << 1) + (energy << 32)) >> 32;
+    energy = clip_q63_to_q31(energy);
+
     /* Set the accumulator to zero */
     acc = 0;