Declaration; Function Use - Freescale Semiconductor DSP56800E User Manual

Function name
MLIB_MulNegRnd_F16as
MLIB_MulNegRnd_F32ls
MLIB_MulNegRnd_F32
MLIB_MulNegRnd_A32

2.35.2 Declaration

The available MLIB_MulNegRnd
frac16_t MLIB_MulNegRnd_F16(frac16_t
frac16_t MLIB_MulNegRnd_F16as(acc32_t
frac32_t MLIB_MulNegRnd_F32ls(frac32_t
frac32_t MLIB_MulNegRnd_F32(frac32_t
acc32_t MLIB_MulNegRnd_A32(acc32_t

2.35.3 Function use

The use of the MLIB_MulNegRnd
#include "mlib.h"
static frac32_t f32Mult1, f32Mult2, f32Result;
void main(void)
{
f32Mult1 = FRAC32(0.3);
f32Mult2 = FRAC32(-0.5);
/* f32Result = round(f32Mult1 * (-f32Mult2)) */
f32Result = MLIB_MulNegRnd_F32(f32Mult1, f32Mult2);
}
Freescale Semiconductor, Inc.
Table 2-35. Function versions (continued)
Input type Result
type
Mult. 1 Mult. 2
acc32_t frac16_t frac16_t
frac32_t frac16_t frac32_t
frac32_t frac32_t frac32_t
acc32_t acc32_t acc32_t
functions have the following declarations:
f16Mult1,
a32Accum,
f32Mult1,
f32Mult1,
a32Mult1, acc32_t
function is shown in the following example:
/* f32Mult1 = 0.3 */
/* f32Mult2 = -0.5 */
MLIB User's Guide, Rev. 2, 10/2015
Description
Negative product of a 32-bit accumulator and a 16-bit
fractional multiplicand; the output is a 16-bit fractional
value, which is rounded to the upper 16 bits of the
fractional portion of the result [16..31]. The output is within
the range <-1 ; 1).
Negative product of a 32-bit fractional multiplicand and a
16-bit fractional multiplicand; the output is rounded to the
upper 32 bits of the fractional portion of the result [16..47].
The output is within the range <-1 ; 1).
Negative product of two 32-bit fractional multiplicands; the
output is rounded to the upper 32 bits of the results
[16..31]. The output is within the range <-1 ; 1).
Product of two 32-bit accumulator multiplicands; the
output is rounded to the the middle bits of the result
[16..47]. The output is within the range <-65536.0 ;
65536.0).
frac16_t f16Mult2)
frac16_t f16Mult)
frac16_t f16Mult2)
frac32_t f32Mult2)
a32Mult1)
Chapter 2 Algorithms in detail
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