not gate with sc_logic

[jsmith125x]

Hi,

 

How to implement a simple not gate with sc_logic type inputs? The ! operator is not defined for this type.

 

 

[Hans64]

Use the bitwise operator ~

 

Hans.

[jsmith125x]

I have got error message for ~ operator too.

[Hans64]

Something must be wrong in your setup, do any other SystemC programs work? What is the error message?

All bitwise operators (& ! ^ ~) should work for sc_logic. You can also use the logical ! after converting it to boolean (.to_bool()).

 

Hans.

[jsmith125x]

...\\notg.h(11): error C2678: binary '~' : no operator found which takes a left-hand operand of type 'sc_core::sc_in<sc_dt::sc_logic>' (or there is no acceptable conversion) [...\\systemc_model.vcxproj]

 

#ifndef notgH

#define notgH


#include "systemc.h"


SC_MODULE(notg)

{

 sc_in<sc_logic> a; // input pins

 sc_out<sc_logic> o; // output pin o


 void proc() { o = ~a; }


 SC_CTOR(notg)    

   {

     SC_METHOD(proc);

     sensitive << a;

   }

};


#endif

[Hans64]

Try: void proc() { o.write(~a.read()); }

 

Hans.

[manikanta.mashetti]

Use internal variable of type logic in the proc copy the input value in to this variable then invert variable and assign to the output port.

[agrawalyogesh04]

Following piece of code should work.

void proc()
{
bool tmp;
tmp = a.read();
o.write(~tmp);
}

[dakupoto]

Hi,

 

How to implement a simple not gate with sc_logic type inputs? The ! operator is not defined for this type.

Hello Sir,

Because of the strongly typed nature of C++ (SystemC is after all a C++ library),

direct conversions that the C language pemits (loosely typed mother langauge

of C++) would not work. There is not much option but to manually convert from

sc_core::sc_logic to the pure and simple bool, do the inversion, and then re-convert

back to sc_logic. It is one of the not so exciting properties of the C++ language

that one has to live with.

[Hans64]

~ is a perfectly legal operator for sc_logic, see the LRM.

 

The problem was the OP was using an implicit method call which confused the compiler. Changing to an explicit .read() method call should fix the problem.

Regards,
Hans.

[dakupoto]

~ is a perfectly legal operator for sc_logic, see the LRM.

 

The problem was the OP was using an implicit method call which confused the compiler. Changing to an explicit .read() method call should fix the problem.

Regards,

Hans.

Dear Sir,

The LRM mentions some things that often do not work with the proof of concept 

SystemC implementation. I have had a number of issues with sc_dt::sc_lv object

in the past, that were solved by using a brute force approach.