Hi All
I tried to implement a simple Task Scheduler in SystemC. It works as follows:
I have three modules "TaskA" , "TaskB" and "CPU". The algorithm works in such a way that the CPU gives full utilization if only one task is present at a time and gives 50% utilization if both the tasks are present. The Arrival times of both the tasks are assigned before the start of the simulation. I was able to implement it with ports and signals, but now i want to measure the performace without ports and signals (i.e) using the C++ and the internal clock of systemc( sc_time_stamp(), sc_start() etc ).
Presently, i have the following:
class Task : sc_module
{
void taskA()
{
....
bool tskA = true;
if(tskA)
{
eventA.notify(10,SC_NS); // Arrival time of A as a Event
tskA = false
}
else
{
outA= true // So that we get the event after 10ns of simualtion time
}
void taskB()
{
.....
bool tskB = true;
if(tskB)
{
eventB.notify(20,SC_NS); // Arrival Time of B as a Event
tskB = false;
}
else
{
outB = true; // To get taskB after 20ns after the start simulation
}
}
SC_CTOR()
{
SC_METHOD(taskA);
SC_METHOD(taskB);
sensitive << eventA;
sensitive << eventB;
}
class CPU: sc_module
{
Task A;
Task B;
void cpu()
{
A.taskA();
B.taskB();
if(outA)
{
//Debug statement
cout << "A arrives @"<< sc_time_stamp() << endl;
some calculation
}
else if (outA && outB)
{
//Debug Statement
cout << "B arrives @" << sc_time_stamp() << endl;
some calculation}
}
}
SC_CTOR(CPU) : A("AT"), B("BT")
{
SC_METHOD(cpu);
sensitive << eventA;
sensitive << eventB;
}
But, the problem is the modules gets executed always. To me more precise:
What I expect as Output is:
A arrives @ 10ns
B arrives @ 20ns
But, What I am getting now is
A arrives @ 10ns
B arrives @ 10ns
A arrives @ 20ns
B arrives @ 20ns
I am not able to figure out where I am going wrong, can anyone please give me suggestions/ point out the msitake i am doing here?
