why did systemc variables change unexpectedly?

[suituse]

the variables are assigned in methods, the methods sensitive at the posedges of some signals. sometimes,the variables changed ,but I cannot see any changes in the signals.

who knows the reason?

 

[nand_gates]

Can you post ur code here?? If not complete code an example code
where the problem exist will do.

 

[suituse]

Thank you for your attention:

sc_in<bool> i_rst_b;

int flag[4];

int buf1;
int buf2;

sc_signal<bool> w_start;
sc_signal<bool> w_update;
sc_signal<bool> w_drop;

SC_METHOD(gen_flags)
sensitive_pos<<w_start<<w_update<<w_drop;
sensitive_neg<<i_rst_b;

gen_flags()
{
if(!i_rst_b.read())
{
for(i=0;i<4;i++)
{
flag=1;
}
}
else
{
;// do nothing
}

if(w_update)
{
flag[buf1]=1;
}
else
{
;// do nothing
}

if(w_start)
{
flag[buf2]=0;
}
else if(w_drop)
{
flag[buf2]=1;
}
else
{
;// do nothing
}

}

w_start and w_update maybe change at the same time.
the same to w_drop and w_update .

flag[3] changed from 1 to 0 while none of the signals were changing.