arm_fir_example/math_helper.h File Reference

Functions
float	arm_snr_f32 (float *pRef, float *pTest, uint32_t buffSize)
	Caluclation of SNR. More...
void	arm_float_to_q12_20 (float *pIn, q31_t *pOut, uint32_t numSamples)
	Converts float to fixed in q12.20 format. More...
void	arm_provide_guard_bits_q15 (q15_t *input_buf, uint32_t blockSize, uint32_t guard_bits)
	Provide guard bits for Input buffer. More...
void	arm_provide_guard_bits_q31 (q31_t *input_buf, uint32_t blockSize, uint32_t guard_bits)
	Provide guard bits for Input buffer. More...
void	arm_float_to_q14 (float *pIn, q15_t *pOut, uint32_t numSamples)
	Converts float to fixed q14. More...
void	arm_float_to_q29 (float *pIn, q31_t *pOut, uint32_t numSamples)
	Converts float to fixed q30 format. More...
void	arm_float_to_q28 (float *pIn, q31_t *pOut, uint32_t numSamples)
	Converts float to fixed q28 format. More...
void	arm_float_to_q30 (float *pIn, q31_t *pOut, uint32_t numSamples)
	Converts float to fixed q30 format. More...
uint32_t	arm_calc_guard_bits (uint32_t num_adds)
	Caluclates number of guard bits. More...
void	arm_apply_guard_bits (float32_t *pIn, uint32_t numSamples, uint32_t guard_bits)
	Apply guard bits to buffer. More...
uint32_t	arm_compare_fixed_q15 (q15_t *pIn, q15_t *pOut, uint32_t numSamples)
	Compare MATLAB Reference Output and ARM Test output. More...
uint32_t	arm_compare_fixed_q31 (q31_t *pIn, q31_t *pOut, uint32_t numSamples)
	Compare MATLAB Reference Output and ARM Test output. More...
uint32_t	arm_calc_2pow (uint32_t guard_bits)
	Calculates pow(2, numShifts) More...

Function Documentation

void arm_apply_guard_bits	(	float32_t *	pIn,
		uint32_t	numSamples,
		uint32_t	guard_bits
	)

Parameters

[in,out]	pIn	pointer to input buffer
[in]	numSamples	number of samples in the input buffer
[in]	guard_bits	guard bits

Returns

none

uint32_t arm_calc_2pow

(

uint32_t

numShifts

)

Parameters

[in]

numShifts

number of shifts

Returns

pow(2, numShifts)

uint32_t arm_calc_guard_bits

(

uint32_t

num_adds

)

Parameters

[in]

num_adds

number of additions

Returns

guard bits The function Caluclates the number of guard bits depending on the numtaps

uint32_t arm_compare_fixed_q15	(	q15_t *	pIn,
		q15_t *	pOut,
		uint32_t	numSamples
	)

Parameters

[in]	pIn	Pointer to Ref buffer
[in]	pOut	Pointer to Test buffer
[in]	numSamples	number of samples in the buffer

Returns

maximum difference

uint32_t arm_compare_fixed_q31	(	q31_t *	pIn,
		q31_t *	pOut,
		uint32_t	numSamples
	)

Parameters

[in]	pIn	Pointer to Ref buffer
[in]	pOut	Pointer to Test buffer
[in]	numSamples	number of samples in the buffer

Returns

maximum difference

void arm_float_to_q12_20	(	float *	pIn,
		q31_t *	pOut,
		uint32_t	numSamples
	)

Parameters

[in]	pIn	pointer to input buffer
[out]	pOut	pointer to outputbuffer
[in]	numSamples	number of samples in the input buffer

Returns

none The function converts floating point values to fixed point(q12.20) values

void arm_float_to_q14	(	float *	pIn,
		q15_t *	pOut,
		uint32_t	numSamples
	)

Parameters

[in]	pIn	pointer to input buffer
[out]	pOut	pointer to output buffer
[in]	numSamples	number of samples in the buffer

Returns

none The function converts floating point values to fixed point values

void arm_float_to_q28	(	float *	pIn,
		q31_t *	pOut,
		uint32_t	numSamples
	)

Parameters

[in]	pIn	pointer to input buffer
[out]	pOut	pointer to output buffer
[in]	numSamples	number of samples in the buffer

Returns

none The function converts floating point values to fixed point values

void arm_float_to_q29	(	float *	pIn,
		q31_t *	pOut,
		uint32_t	numSamples
	)

Parameters

[in]	pIn	pointer to input buffer
[out]	pOut	pointer to output buffer
[in]	numSamples	number of samples in the buffer

Returns

none The function converts floating point values to fixed point values

void arm_float_to_q30	(	float *	pIn,
		q31_t *	pOut,
		uint32_t	numSamples
	)

Parameters

[in]	pIn	pointer to input buffer
[out]	pOut	pointer to output buffer
[in]	numSamples	number of samples in the buffer

Returns

none The function converts floating point values to fixed point values

void arm_provide_guard_bits_q15	(	q15_t *	input_buf,
		uint32_t	blockSize,
		uint32_t	guard_bits
	)

Parameters

[in,out]	input_buf	Pointer to input buffer
[in]	blockSize	block Size
[in]	guard_bits	guard bits

Returns

none The function Provides the guard bits for the buffer to avoid overflow

void arm_provide_guard_bits_q31	(	q31_t *	input_buf,
		uint32_t	blockSize,
		uint32_t	guard_bits
	)

Parameters

[in,out]	input_buf	Pointer to input buffer
[in]	blockSize	block Size
[in]	guard_bits	guard bits

Returns

none The function Provides the guard bits for the buffer to avoid overflow

float arm_snr_f32	(	float *	pRef,
		float *	pTest,
		uint32_t	buffSize
	)

Parameters

[in]	pRef	Pointer to the reference buffer
[in]	pTest	Pointer to the test buffer
[in]	buffSize	total number of samples

Returns

SNR The function Caluclates signal to noise ratio for the reference output and test output