sfrac
Create Simulink.NumericType object
describing signed fractional data type
Syntax
a = sfrac(WordLength) a = sfrac(WordLength,GuardBits)
Description
sfrac( returns
a WordLength)Simulink.NumericType object that describes the
data type of a signed fractional data type with a word size given
by WordLength
sfrac( returns
a WordLength, GuardBits)Simulink.NumericType object that describes the
data type of a signed fractional number. The total word size is given
by WordLengthGuardBits
The most significant (leftmost) bit is the sign bit. The default binary point for this data type is assumed to lie immediately to the right of the sign bit. If guard bits are specified, they lie to the left of the binary point and to right of the sign bit. For example, the structure for an 8-bit signed fractional data type with 4 guard bits is:
Note
sfrac is a legacy function. In new code,
use fixdt instead. In existing code, replace sfrac(WordLength,GuardBits) with fixdt(1,WordLength,(WordLength-1-GuardBits)) and sfrac(WordLength) with fixdt(1,WordLength,(WordLength-1)).
Examples
Define an 8-bit signed fractional data type with 4 guard bits. Note that the range of this data type is -24 = -16 to (1 - 2(1 - 8)).24 = 15.875.
a = sfrac(8,4)
a =
NumericType with properties:
DataTypeMode: 'Fixed-point: binary point scaling'
Signedness: 'Signed'
WordLength: 8
FractionLength: 3
IsAlias: 0
DataScope: 'Auto'
HeaderFile: ''
Description: ''