Declaration - Freescale Semiconductor DSP56800E User Manual

MLIB_MulSat
• Fractional output with fractional inputs - the output is the fractional portion of the
result; the result is within the range <-1 ; 1). The inputs are the fractional values only.
The result may saturate.
• Fractional output with mixed inputs - the output is the fractional portion of the result;
the result is within the range <-1 ; 1). The inputs are the accumulator and fractional
values. The result may saturate.
• Accumulator output - the output is the accumulator type where the result can be out
of the range <-1;1). The result may overflow.
The available versions of the
Function name
MLIB_MulSat_F16 frac16_t
MLIB_MulSat_F16as acc32_t
MLIB_MulSat_F32ss frac16_t
MLIB_MulSat_F32 frac32_t
MLIB_MulSat_A32 acc32_t

2.31.2 Declaration

The available MLIB_MulSat
frac16_t MLIB_MulSat_F16(frac16_t
frac16_t MLIB_MulSat_F16as(acc32_t
frac32_t MLIB_MulSat_F32ss(frac16_t
frac32_t MLIB_MulSat_F32(frac32_t
acc32_t MLIB_MulSat_A32(acc32_t
2.31.3 Function use
The use of the MLIB_MulSat
66
MLIB_MulSat
Table 2-31. Function versions
Input type Result
type
Mult. 1 Mult. 2
frac16_t frac16_t
frac16_t frac16_t
frac16_t frac32_t
frac32_t frac32_t
acc32_t acc32_t
functions have the following declarations:
f16Mult1,
a32Accum,
f16Mult1,
f32Mult1,
a32Mult1, acc32_t
function is shown in the following example:
MLIB User's Guide, Rev. 2, 10/2015
function are shown in the following table:
Description
Product of two 16-bit fractional multiplicands; the output is the
upper 16 bits of the results [16..31]. The output is within the
range <-1 ; 1).
Product of a 32-bit accumulator and a 16-bit fractional
multiplicand; the output is a 16-bit fractional value, which has
the upper 16 bits of the fractional portion of the result [16..31].
The output is within the range <-1 ; 1).
Product of two 16-bit fractional multiplicands; the result is a 32-
bit fractional value. The output is within the range <-1 ; 1).
Product of two 32-bit fractional multiplicands; the output are 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 a
32-bit accumulator, which has the mid 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)
Freescale Semiconductor, Inc.