Mlib_Mul; Available Versions - Freescale Semiconductor DSP56800E User Manual

MLIB_Mul

2.30 MLIB_Mul
The MLIB_Mul functions return the product of two multiplicands. The function does not
saturate the output. See the following equation:

2.30.1 Available versions

This function is available in the following versions:
• 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 overflow.
• 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 overflow.
• 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
Mult. 1
MLIB_Mul_F16 frac16_t
MLIB_Mul_F16as acc32_t
MLIB_Mul_F32ss frac16_t
MLIB_Mul_F32 frac32_t
MLIB_Mul_A32 acc32_t
64
Equation 28. Algorithm formula
MLIB_Mul
Table 2-30. Function versions
Input type Result
type
Mult. 2
frac16_t frac16_t Product of two 16-bit fractional multiplicands; the output are the
upper 16 bits of the results [16..31]. The output is within the range
<-1 ; 1).
frac16_t frac16_t Product of a 32-bit accumulator and a 16-bit fractional multiplicand;
the output is a 16-bit fractional portion, which has the upper 16 bits
of the fractional value of the result [16..31]. The output is within the
range <-1 ; 1).
frac16_t frac32_t Product of two 16-bit fractional multiplicands; the result is a 32-bit
fractional value. The output is within the range <-1 ; 1).
frac32_t frac32_t 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).
acc32_t acc32_t Product of two 32-bit accumulator multiplicands; the output is a 32-
bit accumulator, which has the upper mid bits of the result [16..47].
The output is within the range <-65536.0 ; 65536.0).
MLIB User's Guide, Rev. 2, 10/2015
function are shown in the following table:
Description
Freescale Semiconductor, Inc.