function [sys,x0,str,ts] = generadorDs1(t,x,u,flag,k,s,p)


% Es un gernerador de bit aleatorio con distribucion  uniformemente distribuida 
% i:   Es la  variable  que  se utiliza para el contador.
%y: Variable utilizada para almacenamiento, n: longitud de la secuencia pseudo-aleatoria.

% inicializacion de variable internas.

i=0;
y=0;
u=(k*193);
%(numero de bits que posee en total la trama)
     %(la entradas son los bytes totales de la trama)

  switch flag,
  %%%%%%%%%%%%%%%%%%
  % Initializacion %
  %%%%%%%%%%%%%%%%%%
  % Initialize the states, sample times, and state ordering strings.
  case 0
    [sys,x0,str,ts]=mdlInitializeSizes(u,k,s,p);

  %%%%%%%%%%%
  % salidas %
  %%%%%%%%%%%
  % Devuelve las variables de salidas del bloque S-function
  case 3
    [sys]=mdlOutputs(t,x,u,i,y,k,s,p);


  %%%%%%%%%%%%%%%%%%%%%%%%%%%%
  % Banderas sin manejadores %
  %%%%%%%%%%%%%%%%%%%%%%%%%%%%
  % No hay culminacion de tareas(flag=9) to be handled.
  % tambien, No hay estados continuos o discretos,
  % entonces,las banderas 1 , 2 , 4 no son utilizadas, se regresa una
  % matrix vacia. 
  case { 1, 2, 4, 9 }
    sys=[];

  %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
  % Banderas inesperadas (error handling)%
  %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
  % devuelve un mensaje de error con el numero del manejador de la bandera.
  otherwise
    error(['Unhandled flag = ',num2str(flag)]);

end

% fin del generador

%
%=============================================================================
% mdlInitializeSizes
% devuelve tama駉s, condiciones inicialles, y tiempos de muestreo para la
% S-function.
%=============================================================================

function [sys,x0,str,ts] = mdlInitializeSizes(u,k,s,p)

sizes = simsizes;
sizes.NumContStates  = 0;
sizes.NumDiscStates  = 0;
sizes.NumOutputs     = u;  % dynamically sized
sizes.NumInputs      = 0;  % dynamically sized
sizes.DirFeedthrough = 1;   % has direct feedthrough
sizes.NumSampleTimes = 1;

sys = simsizes(sizes);
str = [];
x0  = [];
ts  = [1/(5503999/688) 0];   % tiempo de muestreo inherente

% end mdlInitializeSizes

%
%=============================================================================
% mdlOutputs
% Return the output vector for the S-function
%=============================================================================
%
function [sys] = mdlOutputs(t,x,u,i,y,k,s,p)
if p==1
   for i=1:u
      y=randn;
        if y>=0.5;
           sys(i) = s*1;
        else
           sys(i) =-s*1;
        end
   end
else
   for i=1:u
       y=randn;
         if y>=0.5;
            sys(i)=s*1;
         else
            sys(i)=0;
         end
   end
end
end
end