How can I convert a uint12 data to an int12 data in Simulink?

I have a 12 bit length 2's complement data that will need to be converted into int12 format in Simulink. The data conversion block in simulink only has output options of int8, int16, int32 or int64. Padding the 12 bit data will resultingly make the conversion inaccurate. Is there a way to convert this the uint12 to int12 in Simulink? Similarly I will have the same issue with converting a uint20 to int20 and uint24 to int24.

Answer 1

[Fangjun Jiang]

If you have the fixed point toolbox, then it is straightforward. Define your data types and then use them anywhere in Simulink, treating them like the built-in types such as int8 or uint8.

>> MyInt12=fixdt(1,12,0);
>> MyUint12=fixdt(0,12,0)
MyUint12 = 
  NumericType with properties:

      DataTypeMode: 'Fixed-point: binary point scaling'
        Signedness: 'Unsigned'
        WordLength: 12
    FractionLength: 0
           IsAlias: 0
         DataScope: 'Auto'
        HeaderFile: ''
       Description: ''

[Thamira Joy Valentine]

Thank you very much! That does exactly what I need.