Tools

Thew following tools are installed locally in /home/esterel/bin/

IDE

Esterel Studio

Compiler

Inria Esterel Compiler (esterel)
Columbia Esterel Compiler (cec)
KEP Kiel Esterel Processor

Managing Traces

Traces of Esterel programs are usually given as ESI or ESO files. The following tools to work with esi and eso files are installed in /home/esterel/bin

eso2esi: removes all outputs from an eso file
esoDiff: compares two eso files and gives the first trace they differ in, if they do
esoPrint: pretty printer for eso Files

Additional tools

v5tov7 is a script based on the CEC to convert Esterel V5 programs into Esterel V7

Semantic differences between v5 / v7 (incomplete)

Modules

In the Esterel v5, the semantic of the instantiation of modules is simply a textual copy and paste, with renaming of signals. In Esterel v7, the behavior is more subtle.

emitting inputs across modules does not work in v7: define that input as output with the same name

Example:

	    main module main_mod:
        input i, env_i; output o; run sub;
        loop await i do
            emit o
        end await end loop;
    end module
    module sub:
        input i,env_i; output i; change input i to output and it works fine sustain {
            i <= env_i
        }
    end module

Similar, reading outputs does not work:

        main module M:
            input I; output O:int init 0; signal S: int init 0 in
                every I do
                    run Count[S/C]; emit O(?S);
                end every
            end signal
        end module
        module Count:
            output C : int; emit C(sat<32>(pre(?C)+1));
        end module

The global initialization does not reach C, hence it is not initialized when I occurs for the first time. Hence C is a local signal, when it is read, but it is a global signal when it is written. So you have to declare C as inputoutput;

New statements

Esterel v7 allows the use of expressions as conditions for strong aborts, but this is somehow tricky. The expression is evaluated before the abort body is executed. When a variable is changed inside the body, making the abort condition true, no abort takes place, not even a weak one.
```
        main module T:
            input I; output O : int;
            var v : int in
                v:=0; abort
                    every I do v:=sat<32>(v+1); end
                when v=3; emit O(v);
            end var
        end module
```

The O will be present in the instant after the third I occurred.

It is now possible to emit signals in the next instant. Unfortunately, this will be silently omitted, if the module terminates in the current instant: main module M:

    main module T:
        signal S in run sub[S/O]; await immediate S; halt; control never reaches this point. end signal
    end module
    module sub:
       output O : reg; emit next O; pause;
    end module

If possible, you can simply add a pause at the end of the module, but of course this can change the overall behavior of the model.

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