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SOLVED: Nevermind, I made some mistakes in calling the wrong methods for writing/reading from ports. Thanks for your attention anyway! I'm trying to implement this example of a memory and a cpu that are communicating. CPU <==> MEM The modules use a single bidirectional data-line for reading/writing. I defined a signal in sc_main: sc_signal<int,SC_MANY_WRITERS> s_memdata; which I connect to the CPU and MEM module through their ports: sc_inout<int> p_memdata; The CPU is writing to the s_memdata signal: p_memdata.write(getrnddata()); As well as the memory: p_data.write( m_data[ m_curAddr ] ); In the debugger I see that the m_curAddr is changing correctly. Yet, the VCD file shows that the signal "data" is not changing when the "address" is changed (as shown in the figure) Actually, the "data" only changes when the cpu is writing to it, not when the memory is. (I was not able to show the function read/write signal because the enum didn't show in the VCD file). It seems to me that there is something going on with the two modules writing to the same channel. I've noticed sc_logic that introduces Z and X values, is this the appropriate way? edit: I've created a simple proof of principle with two writers that talk to a single sc_signal< bool, SC_MANY_WRITERS > which seems to work. So the problem is something different. Thanks for any help or tips. mem_tb.cpp int sc_main(int argc, char* args[]){ Memory * mem; CPU * cpu; mem = new Memory("main_memory"); cpu = new CPU("cpu"); /* sgn */ sc_signal<Memory::Function,SC_MANY_WRITERS> s_memfunc; sc_signal<Memory::RETSignal> s_memsig; sc_signal<int> s_memaddr; sc_signal<int,SC_MANY_WRITERS> s_memdata; sc_clock clk; mem->p_addr(s_memaddr); mem->p_func(s_memfunc); mem->p_data(s_memdata); mem->p_sig(s_memsig); cpu->p_memdata(s_memdata); cpu->p_memaddr(s_memaddr); cpu->p_memsig(s_memsig); cpu->p_memfunc(s_memfunc); mem->clk( clk ); cpu->clk( clk ); std::cout << "Running, CTRL+C to exit..." << std::endl; sc_trace_file * trace = sc_create_vcd_trace_file("trace"); sc_trace(trace, s_memaddr, "addr"); sc_trace(trace, s_memdata, "data"); sc_trace(trace, s_memfunc, "func"); sc_trace(trace, s_memsig, "sig"); sc_start(); sc_close_vcd_trace_file( trace ); return 0; } cpu.h #include <systemc.h> #include "memory.h" #include <boost/random.hpp> SC_MODULE( CPU ) { public: sc_in<bool> clk; sc_in<Memory::RETSignal> p_memsig; sc_out<Memory::Function> p_memfunc; sc_out<int> p_memaddr; sc_inout<int> p_memdata; SC_CTOR( CPU ) { SC_METHOD(exec); sensitive << clk.pos(); dont_initialize(); SC_METHOD(done); sensitive << p_memsig; dont_initialize(); m_waitmem = false; rng.seed( time(NULL) ); dist = new boost::random::uniform_int_distribution<>(0,1<<16); } private: boost::random::mt19937 rng; boost::random::uniform_int_distribution<> *dist; bool m_waitmem; int rand(); Memory::Function getrndfunc(); int getrndaddr(); int getrnddata(); void exec(); void done(); }; cpu.cpp Memory::Function CPU::getrndfunc() { switch( rand() % 2 ) { case 0 : { return Memory::FUNC_READ; } default : { return Memory::FUNC_WRITE; } /* 1, and all other cases... */ } } int CPU::getrndaddr() { return rand() % MEM_SIZE; } int CPU::getrnddata() { return rand(); } int CPU::rand() { return (*dist)(rng); } void CPU::exec() { if(m_waitmem) return; int addr = getrndaddr(); Memory::Function f = getrndfunc(); p_memfunc.write(f); p_memaddr.write(addr); if(f==Memory::FUNC_WRITE) p_memdata.write(getrnddata()); } void CPU::done() { if( p_memsig.read() == Memory::RSIG_NONE ) return; m_waitmem = false; p_memfunc.write(Memory::FUNC_NONE); } memory.h #define MEM_SIZE 512 SC_MODULE( Memory ) { public: enum Function { FUNC_NONE = 0, FUNC_READ = 1, FUNC_WRITE = 2 }; enum RETSignal { RSIG_NONE, RSIG_READ_FIN, RSIG_WRITE_FIN, RSIG_ERR }; sc_in<bool> clk; sc_in<Function> p_func; sc_in<int> p_addr; sc_inout<int> p_data; sc_out<RETSignal> p_sig; SC_CTOR( Memory ){ SC_METHOD(execute); sensitive << clk.neg(); m_clkCnt = 0; m_curAddr = 0; m_curData = 0; m_curFunc = Memory::FUNC_NONE; m_data = new int[MEM_SIZE]; m_writesCnt = 0; m_readsCnt = 0; m_errorsCnt = 0; m_errorCode = 0; } ~Memory(); private: int m_clkCnt; int m_curAddr; int m_curData; Function m_curFunc; int* m_data; int m_errorCode; int m_writesCnt; int m_readsCnt; int m_errorsCnt; RETSignal read(); RETSignal write(); void execute(); }; memory.cpp #include "memory.h" Memory::~Memory() { delete[] m_data; } Memory::RETSignal Memory::read() { if( m_errorCode ) { m_errorsCnt++; return RSIG_ERR; } p_data.write( m_data[ m_curAddr ] ); m_readsCnt++; return RSIG_READ_FIN; } Memory::RETSignal Memory::write() { if( m_errorCode ) { m_errorsCnt++; return RSIG_ERR; } m_data[ m_curAddr ] = m_curData; m_writesCnt++; return RSIG_WRITE_FIN; } void Memory::execute() { if( m_curFunc != FUNC_NONE ) { m_clkCnt++; if( m_clkCnt == 100 ) { RETSignal retSig = RSIG_ERR; switch(m_curFunc){ case FUNC_READ : { retSig = read(); break; } case FUNC_WRITE : { retSig = write(); break; } default : { /* */ } } p_sig.write( retSig ); m_clkCnt = 0; m_curFunc = FUNC_NONE; } return; } if( p_func == FUNC_NONE ) return; m_curFunc = p_func.read(); m_curAddr = p_addr.read(); m_curData = p_data.read(); p_sig.write( RSIG_NONE ); }

Dear reader, I recently started exploring SystemC and SystemC AMS. I'm working through this presentation/tutorial by TU Delft. I'm trying to connect two SCA_TDF modules through a sca_tdf::sca_signal to build the Binary Amplitude Shift Keying modulator. In the constructor of my 'transmitter' I creating two instantiations of a 'mixer' and a 'sine'. mix = new mixer("mixer", rate ); mix->in_bit(in); mix->carrier(wave); mix->mixed(out); sin = new sine("sin", freq, rate ); sin->out(wave); Whereas signals, ports and pointers of this transmitter are defined as follows: sca_tdf::sca_in<bool> in; sca_tdf::sca_out<double> out; mixer * mix; sine * sin; sca_tdf::sca_signal<double> wave; The ports of the mixer are as follows: sca_tdf::sca_in<bool> in_bit; sca_tdf::sca_in<double> carrier; sca_tdf::sca_out<double> mixed; And the port of the sine is as follows: sca_tdf::sca_out<double> out; When I compile and run this, the following message appears: Error: SystemC-AMS: sca_tdf::sca_signal has no driver the following modules are connected to the channel: transmit.mixer In file: ../../../../../src/scams/impl/synchronization/sca_synchronization_alg.cpp:256 I'm pretty sure I've connected this channel (as shown above). Does anyone know what this problem actually means and how I can resolve it? Solved A module that had a sca_out port was inherited from standard SystemC module (SC_MODULE) instead of AMS module (SCA_TDF_MODULE).

Hello to everybody, I would like to know some more information about signals offered by SystemC. How does the signal's structure look like? Is it allocated as an array of data ? Is it just a variable? Do signals have any overhead? For instance what will happen if I use 5000 signals? Thank you in advance !!!!

Hi again! Maybe this is too obvious, but I've been wonderin for a while now and never found the answer (and dared to ask for it ). Is it possible to directly pass whatever comes from an tdf_in port to a tdf_out port? Not only that, is it possible to do it in a sc_module instead of a sca_module? For a better explanation I'll leave a piece of code. Let's say I have: #include <systemc-ams> class some_module : public sc_core::sc_module { public: sca_tdf::sca_in<int> in; sca_tdf::sca_out<int> out; some_module(sc_core::sc_module_name nm); }; Until now I was adding an object, let's call it "tdf_some": #include <systemc-ams> class tdf_some_module : public sca_tdf::sca_module { public: sca_tdf::sca_in<int> in; sca_tdf::sca_out<int> out; tdf_some_module(sc_core::sc_module_name nm) {} void processing() { out.write( in.read() ); } }; Then, in the previous class I would change to: #include <systemc-ams> class some_module : public sc_core::sc_module { public: sca_tdf::sca_in<int> in; sca_tdf::sca_out<int> out; // Add new TDF module tdf_some *ts; some_module(sc_core::sc_module_name nm) { // Instantiate and bind ports ts = new tdf_some("ts"); ts->in(in); ts->out(out); } }; Looks like a very simple question (and I hope so), but I still haven't been able to solve it. Any ideas? Thanks