How can I convert binary data into fixed point data

I want to convert 32 bit binary data to fixed point data fixdt(1,32,16). 32 bit fixed point signed data with 16 bit fractional part. Can u provide me some MATLAB code related to it. Thank you

[SHUAB KHAN]

This link will help you. https://in.mathworks.com/matlabcentral/newsreader/view_thread/288320

[Walter Roberson]

Do you have the fixed point toolbox?

Answer 1

[Andy Bartlett]

First, get the raw integer values in to MATLAB as either uint32 values or int32 values.

Second, use the reinterpretcast function

Example run this code

% Get the raw integers into a uint32 or int32
%   see MATLAB importdata and similar tools for ways
%   to accomplish this step
%
rawInteger = uint32(4275878552)

% Reinterpret data in the appropriate fixed-point type
%
vFixedPoint = reinterpretcast(rawInteger,numerictype(1,32,16))

% Compare hex values before and after
%   just to show the underlying stored integers are preserved
%
hexOrig = lower(dec2hex(rawInteger))
hexFixedPoint = vFixedPoint.hex
compareHexBeforeAfter = [hexOrig;hexFixedPoint]

see this output

rawInteger =
uint32
 4275878552
hexOrig =
  'fedcba98'
vFixedPoint = 
  -2.912711181640625e+02
        DataTypeMode: Fixed-point: binary point scaling
          Signedness: Signed
          WordLength: 32
      FractionLength: 16
hexFixedPoint =
  'fedcba98'
compareHexBeforeAfter  =
2×8 char array
  'fedcba98'
  'fedcba98'

For reference see the help

 >> help reinterpretcast
 reinterpretcast Convert fixed-point or integer data types without changing underlying data
    C = reinterpretcast(A, T) converts the input (integer or fi object) A
    to the data type specified by numerictype object T, without changing
    the underlying (stored integer) data. The result is returned in C.

    The data type of the input A must be fixed point or integer. T must be
    a numerictype object with a fully specified fixed-point data type.  The
    word length of inputs A and T must be the same.

    The reinterpretcast function differs from the MATLAB TYPECAST and CAST
    functions, in that it only operates on fi and integer types, and it
    does not allow the word length of the input to change.

    EXAMPLE:
      %%Convert from signed 8,7 to unsigned 8,0.
      a = fi([-1 pi/4], true, 8, 7)
      %   returns [-1.0000    0.7891] s8,7

      T = numerictype(false, 8, 0);
      b = reinterpretcast(a, T)
      %   returns [128   101] u8,0

      % Their binary representations are identical
      binary_rep = [bin(a);bin(b)]
      %    returns 10000000   01100101
      %            10000000   01100101