How can i implement this code as a simulation uting simulink matlab function block? (changing t and u variables for the time and the step input)

hi, im new in this forum. i want to implement a discrete transfer function algorithm into simulink but i dont know how to get the variables that i use in the matlab code (u=step function, t=simulation time), i want to change this code in a way that i can use it on a simulation in simulink using the matlab function block. my code is:

clc
clear
%simulation time vector
dt=0.04;
t=0:dt:1;

%step
u=ones(size(t));
u(1)=0;

%inicialization
yk_1=0;
yk_2=0;
uk_1=0;
uk_2=0;
%diferential equation solution
for i=1:length(t)
    if i==1
        terminos_u=0.1322*uk_1 + 0.1096*uk_2;
        terminos_y=1.45*yk_1 - 0.5712*yk_2;
        y(i)=terminos_u + terminos_y;
    elseif i==2
        terminos_u=0.1322*u(i-1) + 0.1096*uk_1;
        terminos_y=1.45*y(i-1) - 0.5712*yk_1;
        y(i)=terminos_u + terminos_y;
    else
        terminos_u=0.1322*u(i-1) + 0.1096*u(i-2);
        terminos_y=1.45*y(i-1) - 0.5712*y(i-2);
        y(i)=terminos_u + terminos_y;
    end
end

plot(t,y)

the simulink i want to use is:

i have tried doing this but it wont work in simulink

function y = fcn(u)
%funcion step
persistent yk_1 yk_2 uk_1 uk_2 y_0 u_0

if isempty(u_0)
yk_1=0;
yk_2=0;
uk_1=0;
uk_2=0;    
end

uk_2=uk_1; uk_1=u_0;yk_2=yk_1; yk_1=y_0;

y = 0.1322*uk_1 + 0.1096*uk_2 + 1.45*yk_1 - 0.5712*yk_2;
u_0=u;y_0=y;
end

is says the error:

for all my variables

[Mathieu NOE]

seems y_0 and u_0 are never initialized.

[Jon]

I think you may be misunderstanding the purpose of running a Simulink simulation. You would normally run a Simulink simulation to find the solution to a system differential equations. In your case you already have the solution and it looks like you just want to plot the answer. Please explain further what problem you would like to solve by using Simulink.