Understanding types in SystemC

Question

I am a beginner in SystemC programming and there is one thing I noticed (looking in the SystemC official documentation): all types that I used to deal with in VHDL simulations have not been "ported" to SystemC.

I mean:

Consider std_logic in the VHDL standard library, there is not an equivalent in SystemC, however, in the SystemC documentation, I see many examples using bool.
Consider std_logic_vector, I see no equivalent in SystemC. Instead I can see, in many examples, usage of sc_int.

So I'm thinking that SystemC does not provide types in order to manage single bits or electric signals, but it provides a higher abstraction like in every common C/C++ applications.

Is it so or am I missing something?

score 2 · Answer 1 · answered Apr 05 '11 at 12:46

2

It does have some types: sc_int, sc_bv (bitvector) etc.

answered Apr 05 '11 at 12:46

Marty

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They are provided, but one should add, that usually you indeed use SystemC for higher level modelling (protocolls/busses...). You can bitbang, but when I saw it, it was almost used to model/simulate on a slightly higher level (up to system level). – flolo Apr 05 '11 at 12:58

score 2 · Accepted Answer · answered Jun 24 '11 at 23:46

Consider std_logic in the vhdl standard library, there is not an equivalent in SystemC, however, in the sysc documentation, I see many examples using bool.

Consider std_logic_vector, I see no equivalent in sysc. Instead I can see, in many examples, usage of sc_int.

It's not all that correct.

In SystemC you can use sc_logic and sc_lv< T > as std_logic and std_logic_vector respectively.

You can assign to SC_LOGIC_0 or SC_LOGIC_1 literals to sc_logic.

While you can use integer, hex or even 'bit-specific' literal to assign sc_lv< T > a value.

For example:

class some_device : sc_module
{
    sc_out< sc_lv<32> > address;
    sc_out< sc_logic > write_enable;

    SC_CTOR (some_device)
    {
        write_enable.initialize(SC_LOGIC_0);

        /* The following three lines do the same thing. 
         * Obviously you won't use all three at the same time... */
        address.initialize(0b00001111000011110000111100001111);
        address.initialize(0x0F0F0F0F);
        address.iniziatize(252645135);
    }
}

Hope that helps.

Understanding types in SystemC

2 Answers2