CMSIS-DSP  
CMSIS DSP Software Library
Partial Convolution

Functions

arm_status arm_conv_partial_f32 (const float32_t *pSrcA, uint32_t srcALen, const float32_t *pSrcB, uint32_t srcBLen, float32_t *pDst, uint32_t firstIndex, uint32_t numPoints)
 Partial convolution of floating-point sequences. More...
 
arm_status arm_conv_partial_fast_opt_q15 (const q15_t *pSrcA, uint32_t srcALen, const q15_t *pSrcB, uint32_t srcBLen, q15_t *pDst, uint32_t firstIndex, uint32_t numPoints, q15_t *pScratch1, q15_t *pScratch2)
 Partial convolution of Q15 sequences (fast version). More...
 
arm_status arm_conv_partial_fast_q15 (const q15_t *pSrcA, uint32_t srcALen, const q15_t *pSrcB, uint32_t srcBLen, q15_t *pDst, uint32_t firstIndex, uint32_t numPoints)
 Partial convolution of Q15 sequences (fast version). More...
 
arm_status arm_conv_partial_fast_q31 (const q31_t *pSrcA, uint32_t srcALen, const q31_t *pSrcB, uint32_t srcBLen, q31_t *pDst, uint32_t firstIndex, uint32_t numPoints)
 Partial convolution of Q31 sequences (fast version). More...
 
arm_status arm_conv_partial_opt_q15 (const q15_t *pSrcA, uint32_t srcALen, const q15_t *pSrcB, uint32_t srcBLen, q15_t *pDst, uint32_t firstIndex, uint32_t numPoints, q15_t *pScratch1, q15_t *pScratch2)
 Partial convolution of Q15 sequences. More...
 
arm_status arm_conv_partial_opt_q7 (const q7_t *pSrcA, uint32_t srcALen, const q7_t *pSrcB, uint32_t srcBLen, q7_t *pDst, uint32_t firstIndex, uint32_t numPoints, q15_t *pScratch1, q15_t *pScratch2)
 Partial convolution of Q7 sequences. More...
 
arm_status arm_conv_partial_q15 (const q15_t *pSrcA, uint32_t srcALen, const q15_t *pSrcB, uint32_t srcBLen, q15_t *pDst, uint32_t firstIndex, uint32_t numPoints)
 Partial convolution of Q15 sequences. More...
 
arm_status arm_conv_partial_q31 (const q31_t *pSrcA, uint32_t srcALen, const q31_t *pSrcB, uint32_t srcBLen, q31_t *pDst, uint32_t firstIndex, uint32_t numPoints)
 Partial convolution of Q31 sequences. More...
 
arm_status arm_conv_partial_q7 (const q7_t *pSrcA, uint32_t srcALen, const q7_t *pSrcB, uint32_t srcBLen, q7_t *pDst, uint32_t firstIndex, uint32_t numPoints)
 Partial convolution of Q7 sequences. More...
 

Description

Partial Convolution is equivalent to Convolution except that a subset of the output samples is generated. Each function has two additional arguments. firstIndex specifies the starting index of the subset of output samples. numPoints is the number of output samples to compute. The function computes the output in the range [firstIndex, ..., firstIndex+numPoints-1]. The output array pDst contains numPoints values.

The allowable range of output indices is [0 srcALen+srcBLen-2]. If the requested subset does not fall in this range then the functions return ARM_MATH_ARGUMENT_ERROR. Otherwise the functions return ARM_MATH_SUCCESS.

Note
Refer to arm_conv_f32() for details on fixed point behavior.
Fast Versions
Fast versions are supported for Q31 and Q15 of partial convolution. Cycles for Fast versions are less compared to Q31 and Q15 of partial conv and the design requires the input signals should be scaled down to avoid intermediate overflows.
Opt Versions
Opt versions are supported for Q15 and Q7. Design uses internal scratch buffer for getting good optimisation. These versions are optimised in cycles and consumes more memory (Scratch memory) compared to Q15 and Q7 versions of partial convolution
Long versions:
For convolution of long vectors, those functions are no more adapted and will be very slow. An implementation based upon FFTs should be used.

Function Documentation

◆ arm_conv_partial_f32()

arm_status arm_conv_partial_f32 ( const float32_t pSrcA,
uint32_t  srcALen,
const float32_t pSrcB,
uint32_t  srcBLen,
float32_t pDst,
uint32_t  firstIndex,
uint32_t  numPoints 
)
Parameters
[in]pSrcApoints to the first input sequence
[in]srcALenlength of the first input sequence
[in]pSrcBpoints to the second input sequence
[in]srcBLenlength of the second input sequence
[out]pDstpoints to the location where the output result is written
[in]firstIndexis the first output sample to start with
[in]numPointsis the number of output points to be computed
Returns
execution status

◆ arm_conv_partial_fast_opt_q15()

arm_status arm_conv_partial_fast_opt_q15 ( const q15_t pSrcA,
uint32_t  srcALen,
const q15_t pSrcB,
uint32_t  srcBLen,
q15_t pDst,
uint32_t  firstIndex,
uint32_t  numPoints,
q15_t pScratch1,
q15_t pScratch2 
)

Partial convolution of Q15 sequences (fast version) for Cortex-M3 and Cortex-M4.

Parameters
[in]pSrcApoints to the first input sequence
[in]srcALenlength of the first input sequence
[in]pSrcBpoints to the second input sequence
[in]srcBLenlength of the second input sequence
[out]pDstpoints to the location where the output result is written
[in]firstIndexis the first output sample to start with
[in]numPointsis the number of output points to be computed
[in]pScratch1points to scratch buffer of size max(srcALen, srcBLen) + 2*min(srcALen, srcBLen) - 2
[in]pScratch2points to scratch buffer of size min(srcALen, srcBLen)
Returns
execution status
Remarks
Refer to arm_conv_partial_q15() for a slower implementation of this function which uses a 64-bit accumulator to avoid wrap around distortion.

◆ arm_conv_partial_fast_q15()

arm_status arm_conv_partial_fast_q15 ( const q15_t pSrcA,
uint32_t  srcALen,
const q15_t pSrcB,
uint32_t  srcBLen,
q15_t pDst,
uint32_t  firstIndex,
uint32_t  numPoints 
)

Partial convolution of Q15 sequences (fast version) for Cortex-M3 and Cortex-M4.

Parameters
[in]pSrcApoints to the first input sequence
[in]srcALenlength of the first input sequence
[in]pSrcBpoints to the second input sequence
[in]srcBLenlength of the second input sequence
[out]pDstpoints to the location where the output result is written
[in]firstIndexis the first output sample to start with
[in]numPointsis the number of output points to be computed
Returns
execution status
Remarks
Refer to arm_conv_partial_q15() for a slower implementation of this function which uses a 64-bit accumulator to avoid wrap around distortion.

◆ arm_conv_partial_fast_q31()

arm_status arm_conv_partial_fast_q31 ( const q31_t pSrcA,
uint32_t  srcALen,
const q31_t pSrcB,
uint32_t  srcBLen,
q31_t pDst,
uint32_t  firstIndex,
uint32_t  numPoints 
)

Partial convolution of Q31 sequences (fast version) for Cortex-M3 and Cortex-M4.

Parameters
[in]pSrcApoints to the first input sequence
[in]srcALenlength of the first input sequence
[in]pSrcBpoints to the second input sequence
[in]srcBLenlength of the second input sequence
[out]pDstpoints to the location where the output result is written
[in]firstIndexis the first output sample to start with
[in]numPointsis the number of output points to be computed
Returns
execution status
Remarks
Refer to arm_conv_partial_q31() for a slower implementation of this function which uses a 64-bit accumulator to provide higher precision.

◆ arm_conv_partial_opt_q15()

arm_status arm_conv_partial_opt_q15 ( const q15_t pSrcA,
uint32_t  srcALen,
const q15_t pSrcB,
uint32_t  srcBLen,
q15_t pDst,
uint32_t  firstIndex,
uint32_t  numPoints,
q15_t pScratch1,
q15_t pScratch2 
)
Parameters
[in]pSrcApoints to the first input sequence
[in]srcALenlength of the first input sequence
[in]pSrcBpoints to the second input sequence
[in]srcBLenlength of the second input sequence
[out]pDstpoints to the location where the output result is written
[in]firstIndexis the first output sample to start with
[in]numPointsis the number of output points to be computed
[in]pScratch1points to scratch buffer of size max(srcALen, srcBLen) + 2*min(srcALen, srcBLen) - 2.
[in]pScratch2points to scratch buffer of size min(srcALen, srcBLen).
Returns
execution status
Remarks
Refer to arm_conv_partial_fast_q15() for a faster but less precise version of this function.

◆ arm_conv_partial_opt_q7()

arm_status arm_conv_partial_opt_q7 ( const q7_t pSrcA,
uint32_t  srcALen,
const q7_t pSrcB,
uint32_t  srcBLen,
q7_t pDst,
uint32_t  firstIndex,
uint32_t  numPoints,
q15_t pScratch1,
q15_t pScratch2 
)
Parameters
[in]pSrcApoints to the first input sequence
[in]srcALenlength of the first input sequence
[in]pSrcBpoints to the second input sequence
[in]srcBLenlength of the second input sequence
[out]pDstpoints to the location where the output result is written
[in]firstIndexis the first output sample to start with
[in]numPointsis the number of output points to be computed
[in]pScratch1points to scratch buffer(of type q15_t) of size max(srcALen, srcBLen) + 2*min(srcALen, srcBLen) - 2.
[in]pScratch2points to scratch buffer (of type q15_t) of size min(srcALen, srcBLen).
Returns
execution status

◆ arm_conv_partial_q15()

arm_status arm_conv_partial_q15 ( const q15_t pSrcA,
uint32_t  srcALen,
const q15_t pSrcB,
uint32_t  srcBLen,
q15_t pDst,
uint32_t  firstIndex,
uint32_t  numPoints 
)
Parameters
[in]pSrcApoints to the first input sequence
[in]srcALenlength of the first input sequence
[in]pSrcBpoints to the second input sequence
[in]srcBLenlength of the second input sequence
[out]pDstpoints to the location where the output result is written
[in]firstIndexis the first output sample to start with
[in]numPointsis the number of output points to be computed
Returns
execution status
Remarks
Refer to arm_conv_partial_fast_q15() for a faster but less precise version of this function.
Refer to arm_conv_partial_opt_q15() for a faster implementation of this function using scratch buffers.

◆ arm_conv_partial_q31()

arm_status arm_conv_partial_q31 ( const q31_t pSrcA,
uint32_t  srcALen,
const q31_t pSrcB,
uint32_t  srcBLen,
q31_t pDst,
uint32_t  firstIndex,
uint32_t  numPoints 
)
Parameters
[in]pSrcApoints to the first input sequence
[in]srcALenlength of the first input sequence
[in]pSrcBpoints to the second input sequence
[in]srcBLenlength of the second input sequence
[out]pDstpoints to the location where the output result is written
[in]firstIndexis the first output sample to start with
[in]numPointsis the number of output points to be computed
Returns
execution status
Remarks
Refer to arm_conv_partial_fast_q31() for a faster but less precise implementation of this function.

◆ arm_conv_partial_q7()

arm_status arm_conv_partial_q7 ( const q7_t pSrcA,
uint32_t  srcALen,
const q7_t pSrcB,
uint32_t  srcBLen,
q7_t pDst,
uint32_t  firstIndex,
uint32_t  numPoints 
)
Parameters
[in]pSrcApoints to the first input sequence
[in]srcALenlength of the first input sequence
[in]pSrcBpoints to the second input sequence
[in]srcBLenlength of the second input sequence
[out]pDstpoints to the location where the output result is written
[in]firstIndexis the first output sample to start with
[in]numPointsis the number of output points to be computed
Returns
execution status
Remarks
Refer to arm_conv_partial_opt_q7() for a faster implementation of this function.