How to update values ​​in Simulink

I am creating a simulation with Simulink. I originally wrote the code in MATLAB script, but it is necessary to block it, and it is blocked mainly using MATLAB function. I want to use the value calculated in the previous loop in the next loop. How should I do that? Here is a simple block. Specifically, a wants to take a value from "initial_value" in the first loop, but wants to update the value from "calculate" in the subsequent steps.

Answer 1

[Fangjun Jiang]

All you need is to declare "a" as a persistent variable.

doc persistent

[Shunsuke kishi]

Sorry, I forgot to post the photo. I want to use "a" output by "calculate" in the next loop as shown in this photo. When written in code, it looks like this:

a = 0;
a0 = 0.1;

while(1)
    a = a + a0;
end

Answer 2

[Mark McBroom]

It would be easier to do this with basic simulink blocks. See attached screen shot. Unit delay block by default has initial value of a=0 but can be set to non-zero vaue.