Mlib_Sub - Freescale Semiconductor DSP56800E User Manual

MLIB_Sub

2.54 MLIB_Sub
The MLIB_Sub functions subtract the subtrahend from the minuend. The function does
not saturate the output. See the following equation:
2.54.1 Available versions
This function is available in the following versions:
• Fractional output - the output is the fractional portion of the result; the result is
within the range <-1 ; 1). The result may overflow.
• Accumulator output with fractional inputs - the output is the accumulator type, where
the result can be out of the range <-1 ; 1). The inputs are the fractional values only.
• Accumulator output with mixed inputs - the output is the accumulator type, where
the result can be out of the range <-1 ; 1). The inputs are the accumulator and
fractional values. The result may overflow.
The available versions of the
Function name
Minuend
MLIB_Sub_F16 frac16_t
MLIB_Sub_F32 frac32_t
MLIB_Sub_A32ss frac16_t
MLIB_Sub_A32as acc32_t
2.54.2 Declaration
The available MLIB_Sub
96
Equation 52. Algorithm formula
MLIB_Sub function are shown in the following table.
Table 2-54. Function versions
Input type Result
type
Subtrahend
frac16_t frac16_t
frac32_t frac32_t
frac16_t acc32_t
frac16_t acc32_t
functions have the following declarations:
MLIB User's Guide, Rev. 2, 10/2015
Description
Subtraction of a 16-bit fractional subtrahend from a 16-bit
fractional minuend. The output is within the range <-1 ; 1).
Subtraction of a 32-bit fractional subtrahend from a 32-bit
fractional minuend. The output is within the range <-1 ; 1).
Subtraction of a 16-bit fractional subtrahend from a 16-bit
fractional minuend; the result is a 32-bit accumulator. The
output may be out of the range <-1 ; 1).
Subtraction of a 16-bit fractional subtrahend from a 32-bit
accumulator. The output may be out of the range <-1 ; 1).
Freescale Semiconductor, Inc.