Notify() Using Event Between Two modules

[wasim6691]

//  MODULE 1  WRITING THE OUT1 to Value 1

SC_MODULE(MODULE_1){

public:
    //-------------PORTS DECLARATIONS---------------------------
            sc_in<bool> reset;
            sc_out<bool>  out1  ;  

     // ---event

     sc_event   sig_written;

     public:

      void Process();

public:
    SC_CTOR(MODULE_1){

        SC_METHOD(Process);
        sensitive << reset;

}  

void Process() {

if (reset == 1)

    out1.write(1);

     sig_written.notify();    // to make it runnable within the execution phase and not in the Next delta cycle

}

};

 

//----------------------------------------------------------------------------------------------------------

//  MODULE 2  READING OUTPUT VALUE FROM MODULE_1

SC_MODULE(MODULE_2){

public:
    //-------------PORTS DECLARATIONS---------------------------
            sc_in<bool>  input1;
            sc_out<bool>  out2  ;  

     public:

// HOW TO DEFINE EVENT HERE ?

// PROCESS

void Process();

public:
    SC_CTOR(MODULE_2){

        SC_METHOD(Process);
        sensitive << input1; 

}  

void Process() {

bool x;

x = input1.read();   // reading the Output Value from Module 1. I want to read here 1 because of output

// written in the MODULE_1 is 1

if (x == 1)

    out2.write(1);

   // HOW TO USE EVENT HERE ?   SHARED EVENT

}

};

Hi  I am outputting One value from MODULE 1 and notifying it through sig_written.notify() event to make it detectable in the same execution phase and not in the next delta cycle. Can You tell me How to use the event in the MODULE_2 to detect this event and read the value immediately without going into next delta cycle. thanks  

[Roman Popov]

Do you want to write something like this ?:

Producer process:

out1.write(42);
sig_written.notify();

Consumer process:

wait(sig_written);
out1.read();

In that case you will read current value of signal, not new one (42).

If you want to transfer data immediately between processes, use plain C++ variables. 

 

[wasim6691]

Yes I want to read the new ( 42)  value in the MODULE_2. Can You help me how to modify the above code to read the value immediately. If I use wait()  then console keeps on running towards other processes or the next module which i do not want. thanks

 

[wasim6691]

And The MODULE-1(producer) and MODULE-2(consumer) are different Classes in my code. they are not the processes within one MODULE

[Roman Popov]

10 minutes ago, wasim6691 said:

And The MODULE-1(producer) and MODULE-2(consumer) are different Classes in my code. they are not the processes within one MODULE

Use pointers, references, or write your sc_interface and then use ports/exports.

 

Example with references:

#include <systemc.h>

struct recv_mod : sc_module {

    sc_event &write_event;
    sc_event &recv_event;
    int      &value ;

    recv_mod(::sc_core::sc_module_name, sc_event &write_event, sc_event &recv_event, int &value )
        : write_event(write_event), recv_event(recv_event), value(value)
    {
        SC_HAS_PROCESS(recv_mod);
        SC_THREAD(receiver_thread);
    }

    void receiver_thread() {
        while (1) {
            wait(write_event);
            cout << "Read " << value << " at delta: " << sc_delta_count() << endl;
            recv_event.notify();
        }
    }
};

struct trans_mod : sc_module {

    SC_CTOR(trans_mod) {
        SC_THREAD(transmitter_thread);
    }

    sc_event write_event{"write_event"};
    sc_event recv_event{"recv_event"};
    int value = 0;

    recv_mod recv{"recv", write_event, recv_event, value};

    void transmitter_thread() {
        wait(SC_ZERO_TIME); // need to wait to guarantee that reciever is waiting for event

        for (int i = 0; i < 4; i++) {
            cout << "Write " << i << " at delta: " << sc_delta_count() << endl;
            value = i;
            write_event.notify();
            wait(recv_event);
        }
        sc_stop();
    }
    
};


int sc_main (int argc, char** argv) {
    trans_mod t{"t"};
    sc_start();
}

Simulation result:

Write 0 at delta: 1
Read 0 at delta: 1
Write 1 at delta: 1
Read 1 at delta: 1
Write 2 at delta: 1
Read 2 at delta: 1
Write 3 at delta: 1
Read 3 at delta: 1