1 files changed, 146 insertions, 0 deletions
diff --git a/Drivers/CMSIS/DSP/Source/SupportFunctions/arm_q15_to_q7.c b/Drivers/CMSIS/DSP/Source/SupportFunctions/arm_q15_to_q7.c
new file mode 100644
index 0000000..4f90d56
--- /dev/null
+++ b/Drivers/CMSIS/DSP/Source/SupportFunctions/arm_q15_to_q7.c
@@ -0,0 +1,146 @@
+/* ----------------------------------------------------------------------
+ * Project:      CMSIS DSP Library
+ * Title:        arm_q15_to_q7.c
+ * Description:  Converts the elements of the Q15 vector to Q7 vector
+ *
+ * $Date:        18. March 2019
+ * $Revision:    V1.6.0
+ *
+ * Target Processor: Cortex-M cores
+ * -------------------------------------------------------------------- */
+/*
+ * Copyright (C) 2010-2019 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"
+
+/**
+  @ingroup groupSupport
+ */
+
+/**
+  @addtogroup q15_to_x
+  @{
+ */
+
+/**
+  @brief         Converts the elements of the Q15 vector to Q7 vector.
+  @param[in]     pSrc       points to the Q15 input vector
+  @param[out]    pDst       points to the Q7 output vector
+  @param[in]     blockSize  number of samples in each vector
+  @return        none
+
+  @par           Details
+                   The equation used for the conversion process is:
+  <pre>
+      pDst[n] = (q7_t) pSrc[n] >> 8;   0 <= n < blockSize.
+  </pre>
+ */
+
+void arm_q15_to_q7(
+  const q15_t * pSrc,
+        q7_t * pDst,
+        uint32_t blockSize)
+{
+        uint32_t blkCnt;                               /* Loop counter */
+  const q15_t *pIn = pSrc;                             /* Source pointer */
+
+#if defined (ARM_MATH_LOOPUNROLL) && defined (ARM_MATH_DSP)
+        q31_t in1, in2;
+        q31_t out1, out2;
+#endif
+
+#if defined (ARM_MATH_LOOPUNROLL)
+
+  /* Loop unrolling: Compute 4 outputs at a time */
+  blkCnt = blockSize >> 2U;
+
+  while (blkCnt > 0U)
+  {
+    /* C = (q7_t) A >> 8 */
+
+    /* Convert from q15 to q7 and store result in destination buffer */
+#if defined (ARM_MATH_DSP)
+
+    in1 = read_q15x2_ia ((q15_t **) &pIn);
+    in2 = read_q15x2_ia ((q15_t **) &pIn);
+
+#ifndef ARM_MATH_BIG_ENDIAN
+
+    out1 = __PKHTB(in2, in1, 16);
+    out2 = __PKHBT(in2, in1, 16);
+
+#else
+
+    out1 = __PKHTB(in1, in2, 16);
+    out2 = __PKHBT(in1, in2, 16);
+
+#endif /* #ifndef ARM_MATH_BIG_ENDIAN */
+
+    /* rotate packed value by 24 */
+    out2 = ((uint32_t) out2 << 8) | ((uint32_t) out2 >> 24);
+
+    /* anding with 0xff00ff00 to get two 8 bit values */
+    out1 = out1 & 0xFF00FF00;
+    /* anding with 0x00ff00ff to get two 8 bit values */
+    out2 = out2 & 0x00FF00FF;
+
+    /* oring two values(contains two 8 bit values) to get four packed 8 bit values */
+    out1 = out1 | out2;
+
+    /* store 4 samples at a time to destiantion buffer */
+    write_q7x4_ia (&pDst, out1);
+
+#else
+
+    *pDst++ = (q7_t) (*pIn++ >> 8);
+    *pDst++ = (q7_t) (*pIn++ >> 8);
+    *pDst++ = (q7_t) (*pIn++ >> 8);
+    *pDst++ = (q7_t) (*pIn++ >> 8);
+
+#endif /* #if defined (ARM_MATH_DSP) */
+
+    /* Decrement loop counter */
+    blkCnt--;
+  }
+
+  /* Loop unrolling: Compute remaining outputs */
+  blkCnt = blockSize % 0x4U;
+
+#else
+
+  /* Initialize blkCnt with number of samples */
+  blkCnt = blockSize;
+
+#endif /* #if defined (ARM_MATH_LOOPUNROLL) */
+
+  while (blkCnt > 0U)
+  {
+    /* C = (q7_t) A >> 8 */
+
+    /* Convert from q15 to q7 and store result in destination buffer */
+    *pDst++ = (q7_t) (*pIn++ >> 8);
+
+    /* Decrement loop counter */
+    blkCnt--;
+  }
+
+}
+
+/**
+  @} end of q15_to_x group
+ */