Official ARM version: v5.6.0HEADmaster

1 files changed, 99 insertions, 0 deletions

diff --git a/DSP/Source/TransformFunctions/arm_bitreversal2.c b/DSP/Source/TransformFunctions/arm_bitreversal2.c
new file mode 100644
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+++ b/DSP/Source/TransformFunctions/arm_bitreversal2.c
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+/* ----------------------------------------------------------------------
+ * Project:      CMSIS DSP Library
+ * Title:        arm_bitreversal2.c
+ * Description:  Bitreversal functions
+ *
+ * $Date:        18. March 2019
+ * $Revision:    V1.0.0
+ *
+ * Target Processor: Cortex-M cores
+ * -------------------------------------------------------------------- */
+/*
+ * Copyright (C) 2019 ARM Limited or its affiliates. All rights reserved.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * Licensed under the Apache License, Version 2.0 (the License); you may
+ * not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an AS IS BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "arm_math.h"
+#include "arm_common_tables.h"
+
+/**
+  @brief         In-place 32 bit reversal function.
+  @param[in,out] pSrc        points to in-place buffer of unknown 32-bit data type
+  @param[in]     bitRevLen   bit reversal table length
+  @param[in]     pBitRevTab  points to bit reversal table
+  @return        none
+*/
+
+void arm_bitreversal_32(
+        uint32_t *pSrc, 
+  const uint16_t bitRevLen, 
+  const uint16_t *pBitRevTab)
+{
+  uint32_t a, b, i, tmp;
+
+  for (i = 0; i < bitRevLen; )
+  {
+     a = pBitRevTab[i    ] >> 2;
+     b = pBitRevTab[i + 1] >> 2;
+
+     //real
+     tmp = pSrc[a];
+     pSrc[a] = pSrc[b];
+     pSrc[b] = tmp;
+
+     //complex
+     tmp = pSrc[a+1];
+     pSrc[a+1] = pSrc[b+1];
+     pSrc[b+1] = tmp;
+
+    i += 2;
+  }
+}
+
+
+/**
+  @brief         In-place 16 bit reversal function.
+  @param[in,out] pSrc        points to in-place buffer of unknown 16-bit data type
+  @param[in]     bitRevLen   bit reversal table length
+  @param[in]     pBitRevTab  points to bit reversal table
+  @return        none
+*/
+
+void arm_bitreversal_16(
+        uint16_t *pSrc, 
+  const uint16_t bitRevLen, 
+  const uint16_t *pBitRevTab)
+{
+  uint16_t a, b, i, tmp;
+
+  for (i = 0; i < bitRevLen; )
+  {
+     a = pBitRevTab[i    ] >> 2;
+     b = pBitRevTab[i + 1] >> 2;
+
+     //real
+     tmp = pSrc[a];
+     pSrc[a] = pSrc[b];
+     pSrc[b] = tmp;
+
+     //complex
+     tmp = pSrc[a+1];
+     pSrc[a+1] = pSrc[b+1];
+     pSrc[b+1] = tmp;
+
+    i += 2;
+  }
+}