CMSISDSP
Version 1.5.2
CMSIS DSP Software Library

Functions  
void  arm_conv_f32 (float32_t *pSrcA, uint32_t srcALen, float32_t *pSrcB, uint32_t srcBLen, float32_t *pDst) 
Convolution of floatingpoint sequences. More...  
void  arm_conv_fast_opt_q15 (q15_t *pSrcA, uint32_t srcALen, q15_t *pSrcB, uint32_t srcBLen, q15_t *pDst, q15_t *pScratch1, q15_t *pScratch2) 
Convolution of Q15 sequences (fast version) for CortexM3 and CortexM4. More...  
void  arm_conv_fast_q15 (q15_t *pSrcA, uint32_t srcALen, q15_t *pSrcB, uint32_t srcBLen, q15_t *pDst) 
Convolution of Q15 sequences (fast version) for CortexM3 and CortexM4. More...  
void  arm_conv_fast_q31 (q31_t *pSrcA, uint32_t srcALen, q31_t *pSrcB, uint32_t srcBLen, q31_t *pDst) 
Convolution of Q31 sequences (fast version) for CortexM3 and CortexM4. More...  
void  arm_conv_opt_q15 (q15_t *pSrcA, uint32_t srcALen, q15_t *pSrcB, uint32_t srcBLen, q15_t *pDst, q15_t *pScratch1, q15_t *pScratch2) 
Convolution of Q15 sequences. More...  
void  arm_conv_opt_q7 (q7_t *pSrcA, uint32_t srcALen, q7_t *pSrcB, uint32_t srcBLen, q7_t *pDst, q15_t *pScratch1, q15_t *pScratch2) 
Convolution of Q7 sequences. More...  
void  arm_conv_q15 (q15_t *pSrcA, uint32_t srcALen, q15_t *pSrcB, uint32_t srcBLen, q15_t *pDst) 
Convolution of Q15 sequences. More...  
void  arm_conv_q31 (q31_t *pSrcA, uint32_t srcALen, q31_t *pSrcB, uint32_t srcBLen, q31_t *pDst) 
Convolution of Q31 sequences. More...  
void  arm_conv_q7 (q7_t *pSrcA, uint32_t srcALen, q7_t *pSrcB, uint32_t srcBLen, q7_t *pDst) 
Convolution of Q7 sequences. More...  
Convolution is a mathematical operation that operates on two finite length vectors to generate a finite length output vector. Convolution is similar to correlation and is frequently used in filtering and data analysis. The CMSIS DSP library contains functions for convolving Q7, Q15, Q31, and floatingpoint data types. The library also provides fast versions of the Q15 and Q31 functions on CortexM4 and CortexM3.
a[n]
and b[n]
be sequences of length srcALen
and srcBLen
samples respectively. Then the convolutionc[n] = a[n] * b[n]
c[n]
is of length srcALen + srcBLen  1
and is defined over the interval n=0, 1, 2, ..., srcALen + srcBLen  2
. pSrcA
points to the first input vector of length srcALen
and pSrcB
points to the second input vector of length srcBLen
. The output result is written to pDst
and the calling function must allocate srcALen+srcBLen1
words for the result.a[n]
and b[n]
are convolved, the signal b[n]
slides over a[n]
. For each offset n
, the overlapping portions of a[n] and b[n] are multiplied and summed together.a[n] * b[n] = b[n] * a[n].
FixedPoint Behavior
Fast Versions
Opt Versions
void arm_conv_f32  (  float32_t *  pSrcA, 
uint32_t  srcALen,  
float32_t *  pSrcB,  
uint32_t  srcBLen,  
float32_t *  pDst  
) 
[in]  *pSrcA  points to the first input sequence. 
[in]  srcALen  length of the first input sequence. 
[in]  *pSrcB  points to the second input sequence. 
[in]  srcBLen  length of the second input sequence. 
[out]  *pDst  points to the location where the output result is written. Length srcALen+srcBLen1. 
void arm_conv_fast_opt_q15  (  q15_t *  pSrcA, 
uint32_t  srcALen,  
q15_t *  pSrcB,  
uint32_t  srcBLen,  
q15_t *  pDst,  
q15_t *  pScratch1,  
q15_t *  pScratch2  
) 
[in]  *pSrcA  points to the first input sequence. 
[in]  srcALen  length of the first input sequence. 
[in]  *pSrcB  points to the second input sequence. 
[in]  srcBLen  length of the second input sequence. 
[out]  *pDst  points to the location where the output result is written. Length srcALen+srcBLen1. 
[in]  *pScratch1  points to scratch buffer of size max(srcALen, srcBLen) + 2*min(srcALen, srcBLen)  2. 
[in]  *pScratch2  points to scratch buffer of size min(srcALen, srcBLen). 
Scaling and Overflow Behavior:
arm_conv_q15()
for a slower implementation of this function which uses 64bit accumulation to avoid wrap around distortion. References __PKHBT, __SIMD32, __SMLAD(), __SMLADX(), _SIMD32_OFFSET, arm_copy_q15(), arm_fill_q15(), srcALen, and srcBLen.
void arm_conv_fast_q15  (  q15_t *  pSrcA, 
uint32_t  srcALen,  
q15_t *  pSrcB,  
uint32_t  srcBLen,  
q15_t *  pDst  
) 
[in]  *pSrcA  points to the first input sequence. 
[in]  srcALen  length of the first input sequence. 
[in]  *pSrcB  points to the second input sequence. 
[in]  srcBLen  length of the second input sequence. 
[out]  *pDst  points to the location where the output result is written. Length srcALen+srcBLen1. 
Scaling and Overflow Behavior:
arm_conv_q15()
for a slower implementation of this function which uses 64bit accumulation to avoid wrap around distortion. References __PKHBT, __SIMD32, __SMLAD(), __SMLADX(), _SIMD32_OFFSET, srcALen, and srcBLen.
void arm_conv_fast_q31  (  q31_t *  pSrcA, 
uint32_t  srcALen,  
q31_t *  pSrcB,  
uint32_t  srcBLen,  
q31_t *  pDst  
) 
[in]  *pSrcA  points to the first input sequence. 
[in]  srcALen  length of the first input sequence. 
[in]  *pSrcB  points to the second input sequence. 
[in]  srcBLen  length of the second input sequence. 
[out]  *pDst  points to the location where the output result is written. Length srcALen+srcBLen1. 
Scaling and Overflow Behavior:
arm_conv_q31()
for a slower implementation of this function which uses 64bit accumulation to provide higher precision. void arm_conv_opt_q15  (  q15_t *  pSrcA, 
uint32_t  srcALen,  
q15_t *  pSrcB,  
uint32_t  srcBLen,  
q15_t *  pDst,  
q15_t *  pScratch1,  
q15_t *  pScratch2  
) 
[in]  *pSrcA  points to the first input sequence. 
[in]  srcALen  length of the first input sequence. 
[in]  *pSrcB  points to the second input sequence. 
[in]  srcBLen  length of the second input sequence. 
[out]  *pDst  points to the location where the output result is written. Length srcALen+srcBLen1. 
[in]  *pScratch1  points to scratch buffer of size max(srcALen, srcBLen) + 2*min(srcALen, srcBLen)  2. 
[in]  *pScratch2  points to scratch buffer of size min(srcALen, srcBLen). 
Scaling and Overflow Behavior:
arm_conv_fast_q15()
for a faster but less precise version of this function for CortexM3 and CortexM4. References __PKHBT, __SIMD32, __SMLALD(), __SMLALDX(), _SIMD32_OFFSET, arm_copy_q15(), arm_fill_q15(), srcALen, and srcBLen.
void arm_conv_opt_q7  (  q7_t *  pSrcA, 
uint32_t  srcALen,  
q7_t *  pSrcB,  
uint32_t  srcBLen,  
q7_t *  pDst,  
q15_t *  pScratch1,  
q15_t *  pScratch2  
) 
[in]  *pSrcA  points to the first input sequence. 
[in]  srcALen  length of the first input sequence. 
[in]  *pSrcB  points to the second input sequence. 
[in]  srcBLen  length of the second input sequence. 
[out]  *pDst  points to the location where the output result is written. Length srcALen+srcBLen1. 
[in]  *pScratch1  points to scratch buffer(of type q15_t) of size max(srcALen, srcBLen) + 2*min(srcALen, srcBLen)  2. 
[in]  *pScratch2  points to scratch buffer (of type q15_t) of size min(srcALen, srcBLen). 
Scaling and Overflow Behavior:
max(srcALen, srcBLen)<131072
. The 18.14 result is then truncated to 18.7 format by discarding the low 7 bits and then saturated to 1.7 format. References __PACKq7, __PKHBT, __SIMD32, __SMLAD(), __SMLADX(), _SIMD32_OFFSET, arm_fill_q15(), srcALen, and srcBLen.
void arm_conv_q15  (  q15_t *  pSrcA, 
uint32_t  srcALen,  
q15_t *  pSrcB,  
uint32_t  srcBLen,  
q15_t *  pDst  
) 
[in]  *pSrcA  points to the first input sequence. 
[in]  srcALen  length of the first input sequence. 
[in]  *pSrcB  points to the second input sequence. 
[in]  srcBLen  length of the second input sequence. 
[out]  *pDst  points to the location where the output result is written. Length srcALen+srcBLen1. 
Scaling and Overflow Behavior:
arm_conv_fast_q15()
for a faster but less precise version of this function for CortexM3 and CortexM4.arm_conv_opt_q15()
for a faster implementation of this function using scratch buffers. References __PKHBT, __SIMD32, __SMLALD(), __SMLALDX(), _SIMD32_OFFSET, srcALen, and srcBLen.
void arm_conv_q31  (  q31_t *  pSrcA, 
uint32_t  srcALen,  
q31_t *  pSrcB,  
uint32_t  srcBLen,  
q31_t *  pDst  
) 
[in]  *pSrcA  points to the first input sequence. 
[in]  srcALen  length of the first input sequence. 
[in]  *pSrcB  points to the second input sequence. 
[in]  srcBLen  length of the second input sequence. 
[out]  *pDst  points to the location where the output result is written. Length srcALen+srcBLen1. 
Scaling and Overflow Behavior:
arm_conv_fast_q31()
for a faster but less precise implementation of this function for CortexM3 and CortexM4. [in]  *pSrcA  points to the first input sequence. 
[in]  srcALen  length of the first input sequence. 
[in]  *pSrcB  points to the second input sequence. 
[in]  srcBLen  length of the second input sequence. 
[out]  *pDst  points to the location where the output result is written. Length srcALen+srcBLen1. 
Scaling and Overflow Behavior:
max(srcALen, srcBLen)<131072
. The 18.14 result is then truncated to 18.7 format by discarding the low 7 bits and then saturated to 1.7 format.arm_conv_opt_q7()
for a faster implementation of this function.