Vector Shift

Collaboration diagram for Vector Shift:

Functions
void	tpt_shift_q15 (q15_t *aOutData, const q15_t *aInData, int8_t aShiftBits, uint32_t aCount)
	Shifts the elements of a Q15 vector a specified number of bits. More...
void	tpt_shift_q31 (q31_t *aOutData, const q31_t *aInData, int8_t aShiftBits, uint32_t aCount)
	Shifts the elements of a Q15 vector a specified number of bits. More...
void	tpt_shift_q7 (q7_t *aOutData, const q7_t *aInData, int8_t aShiftBits, uint32_t aCount)
	Shifts the elements of a Q7 vector a specified number of bits. More...

Detailed Description

Shifts the elements of a fixed-point vector by a specified number of bits. There are separate functions for Q7, Q15, and Q31 data types. The underlying algorithm used is:

    aOutData[n] = aInData[n] << aShiftBits,     0 <= n < aCount.
  

If aShiftBits is positive then the elements of the vector are shifted to the left. If aShiftBits is negative then the elements of the vector are shifted to the right.

The functions support in-place computation allowing the source and destination pointers to reference the same memory buffer.

Function Documentation

tpt_shift_q15()

void tpt_shift_q15	(	q15_t *	aOutData,
		const q15_t *	aInData,
		int8_t	aShiftBits,
		uint32_t	aCount
	)

Shifts the elements of a Q15 vector a specified number of bits.

Parameters

[out]	aOutData	points to the output vector.
[in]	aInData	points to the input vector.
[in]	aShiftBits	number of bits to shift. A positive value shifts left; a negative value shifts right.
[in]	aCount	number of samples in each vector

Returns

none

Scaling and Overflow Behavior

The function uses saturating arithmetic. Results outside of the allowable Q15 range [0x8000 0x7FFF] are saturated.

tpt_shift_q31()

void tpt_shift_q31	(	q31_t *	aOutData,
		const q31_t *	aInData,
		int8_t	aShiftBits,
		uint32_t	aCount
	)

Shifts the elements of a Q15 vector a specified number of bits.

Parameters

[out]	aOutData	points to the output vector
[in]	aInData	points to the input vector
[in]	aShiftBits	number of bits to shift. A positive value shifts left; a negative value shifts right.
[in]	aCount	number of samples in each vector

Returns

none

Scaling and Overflow Behavior

The function uses saturating arithmetic. Results outside of the allowable Q31 range [0x80000000 0x7FFFFFFF] are saturated.

tpt_shift_q7()

void tpt_shift_q7	(	q7_t *	aOutData,
		const q7_t *	aInData,
		int8_t	aShiftBits,
		uint32_t	aCount
	)

Shifts the elements of a Q7 vector a specified number of bits.

Parameters

[out]	aOutData	points to the output vector
[in]	aInData	points to the input vector
[in]	aShiftBits	number of bits to shift. A positive value shifts left; a negative value shifts right.
[in]	aCount	number of samples in each vector

Returns

none

Scaling and Overflow Behavior

The function uses saturating arithmetic. Results outside of the allowable Q7 range [0x80 0x7F] are saturated.