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Hello All, I am modeling A2D that uses a successive approximation algorithm. I have modeled A2D converter in SystemC and SystemC-AMS. But both of the models give me some errors. SC model ends up with infinite loop, and SC-AMS model ends with segmentation fault the models are as follows: SC models: Location of the while loop could be the serious problem. I have tried changing the location in side switch statement, but error persists. //error message: stage 1: start edge stage 1: start edge stage 1: start edge stage 1: start edge stage 1: start edge stage 1: start edge stage 1: start edge ...... infinite loop // SC_A2D.h #include<systemc.h> enum adc_state {input, convert}; SC_MODULE(A2D_module) { sc_in_clk clk; sc_in_clk start; sc_in<double> ain; sc_out<sc_logic> eoc; sc_out<sc_lv<8> > dout; sc_signal <adc_state> status; void conversion_logic(); // void next_state_logic(); SC_CTOR(A2D_module) { SC_CTHREAD(conversion_logic, start.pos()); } }; //SC_A2D.cpp #include <SC_A2D.h> void A2D_module::conversion_logic() { eoc = SC_LOGIC_0; dout = "00000000"; double thresh, Vtemp; sc_lv<8> dtemp; int bit_cnt = 8; status = input; while(bit_cnt > 0) { switch (status){ cout << "begin !!!"; case input: if (start == 1) { cout << "stage 1: start edge" << endl; thresh = 5.0; Vtemp = ain; eoc = SC_LOGIC_0; status = convert; } break; case convert: if (clk == 1) { cout << "stage 2: clk edge" << endl; thresh = thresh/2.0; if (Vtemp > thresh) { cout << "stage 3: Vtemp > thresh" << endl; dtemp[bit_cnt]= '1'; Vtemp = Vtemp- thresh; } else { dtemp[bit_cnt]= '0'; } if (bit_cnt > 0) { cout << "stage 4: bit_cnt > 0" << endl; bit_cnt = bit_cnt - 1; } else { cout << "last stage: conversion" << endl; dout = dtemp; status = input; wait(10, SC_US); eoc = SC_LOGIC_1; } } break; } // end switch } // end while } // end method conversion_logic ------------------------------------------------------------------------------------------------------------- SC-AMS models: which gives segmentation fault // Error message: stage 1: Read Input stage 3: Convert Input stage 1: Read Input stage 2 : start edge stage 3: Convert Input stage 4: clk edge !!! bit_cnt = 7 stage 1: Read Input stage 3: Convert Input stage 1: Read Input stage 3: Convert Input stage 4: clk edge !!! Segmentation fault // A2D.h #include <systemc-ams> #include <systemc> #include <stdio.h> using namespace std; //ref: VHDL-AMS Model of A2D converter given in System designer's guide to VHDL-AMS on page 287 SCA_TDF_MODULE (a2d_nbit) { //port declaration sca_tdf::sca_in<double> ain; // analog input pin sca_tdf::sca_de::sca_in<bool> clk; //clock signal sca_tdf::sca_de::sca_in<bool> start; //clock signal sca_tdf::sca_de::sca_out<sc_dt::sc_logic> eoc; //end of conversion pin sca_tdf::sca_de::sca_out<sc_dt::sc_lv<8> > dout; //digitalized output a2d_nbit(sc_core::sc_module_name nm, double Vmax_ = 5.0, double delay_ = 10.0e-6, int bit_range_ = 8, bool start_x_ = 0, bool clk_x_ = 0): ain("ain"), start("start"),clk("clk"), eoc("eoc"), dout("dout"), Vmax(Vmax_), delay(delay_), bit_range(bit_range_), start_x(start_x_), clk_x(clk_x_){} void set_attributes() { set_timestep(50, sc_core::SC_US); eoc.set_delay(1); } void initialize() { eoc.initialize(sc_dt::SC_LOGIC_0); } void processing(); private: double delay; // ADC conversion time double Vmax; int bit_range; bool clk_x; bool start_x; }; // A2D.cpp void a2d_nbit :: processing() { // double Vin = ain.read(); double thresh; //Threshold to test input voltage double Vtemp; //snapshot of input voltage when conversion starts sc_dt::sc_lv<8> dtemp; //temparary output data enum state {input, convert}; int bit_cnt; state status = input; switch(status) // ref: systemC state machine example in SystemC user guide on page 171 { case input : cout << "stage 1: Read Input" << endl; if((start == true) && (start_x == false)) //if (start == true) { cout << "stage 2 : start edge" << endl; bit_cnt = bit_range; thresh = Vmax; Vtemp = ain; eoc = sc_dt::sc_logic('0'); } case convert: cout << "stage 3: Convert Input" << endl; if ((clk == true) && (clk_x == false)) //if (clk == true) { cout << "stage 4: clk edge !!!" << endl; thresh = thresh/2.0; if (Vtemp > thresh) { dtemp[bit_cnt]= '1'; Vtemp = Vtemp - thresh; } else { dtemp[bit_cnt]= '0'; } if (bit_cnt > 0) { bit_cnt = bit_cnt - 1; cout << " bit_cnt = " << bit_cnt << endl; } else { dout = dtemp; eoc = sc_dt::sc_logic('1'); status = input; } break; } default: break; } // end switch start_x = start; clk_x = clk; } ---------------------------------------------------------------------------------------------------------------- // voltage source: dummy_source.h #include<systemc-ams> #include<systemc> #include<iostream.h> #include<fstream.h> using namespace std; SCA_TDF_MODULE (dummy_src) { // sca_tdf::sca_de::sca_out<double> output; sca_tdf:: sca_out<double> output; ifstream infile; double val; dummy_src(sc_core::sc_module_name): output("output"){} void set_attributes() { set_timestep(50, sc_core::SC_US); infile.open("datalog.txt"); } void processing () { if (infile >> val) { output.write(val); } else { output.write(0.0); } } }; ------------------------------------------------------------------------------------------------------------- // top_level_entity : interface.h #include<systemc-ams> #include<systemc> #include<A2D.h> //#include<SC_A2D.h> #include<dummy_source.h> using namespace std; using namespace sc_core; SC_MODULE (interface2) { // A2D_module a2d; a2d_nbit a2d; dummy_src input_vtg; sc_core::sc_clock clk1; sc_core::sc_clock start1; SC_CTOR(interface2) :in("in"), out("out"), a2d("a2d"), input_vtg("input_vtg"), clk1("clk1", 100, sc_core::SC_US, 0.5), start1("start1", 200, sc_core::SC_US, 0.5), eoc("eoc") { input_vtg.output(in); a2d.ain(in); a2d.start(start1.signal()); a2d.clk(clk1.signal()); a2d.eoc(eoc); a2d.dout(out); } public: // sc_core::sc_signal <double> in; sca_tdf::sca_signal<double> in; sc_core::sc_signal<sc_dt::sc_lv<8> > out; sc_core::sc_signal<sc_logic> eoc; }; // top_level_entity: interface2.cpp #include<systemc-ams.h> #include<systemc.h> #include<iomanip> #include<interface2.h> int sc_main(int argc, char* argv[]) { interface2 if2_dut("if2_dut"); sca_util :: sca_trace_file* atfs = sca_util :: sca_create_tabular_trace_file("if2.dat"); sca_util :: sca_trace(atfs, if2_dut.clk1, "\tCLK"); sca_util :: sca_trace(atfs, if2_dut.start1, "\tSTART"); sca_util :: sca_trace(atfs, if2_dut.in, "\tINPUT"); sca_util :: sca_trace(atfs, if2_dut.out, "\tOUTPUT"); sca_util :: sca_trace(atfs, if2_dut.eoc, "\tEOC"); sc_start(400, SC_US); sca_util :: sca_close_tabular_trace_file (atfs); return 0; } -------------------

Hello All, I am modeling A2D that uses a successive approximation algorithm. I have modeled A2D converter in SystemC and SystemC-AMS. But both of the models give me some errors. SC model ends up with infinite loop, and SC-AMS model ends with segmentation fault the models are as follows: SC models: Location of the while loop could be the serious problem. I have tried changing the location in side switch statement, but error persists. //error message: stage 1: start edge stage 1: start edge stage 1: start edge stage 1: start edge stage 1: start edge stage 1: start edge stage 1: start edge ...... infinite loop // SC_A2D.h #include<systemc.h> enum adc_state {input, convert}; SC_MODULE(A2D_module) { sc_in_clk clk; sc_in_clk start; sc_in<double> ain; sc_out<sc_logic> eoc; sc_out<sc_lv<8> > dout; sc_signal <adc_state> status; void conversion_logic(); // void next_state_logic(); SC_CTOR(A2D_module) { SC_CTHREAD(conversion_logic, start.pos()); } }; //SC_A2D.cpp #include <SC_A2D.h> void A2D_module::conversion_logic() { eoc = SC_LOGIC_0; dout = "00000000"; double thresh, Vtemp; sc_lv<8> dtemp; int bit_cnt = 8; status = input; while(bit_cnt > 0) { switch (status){ cout << "begin !!!"; case input: if (start == 1) { cout << "stage 1: start edge" << endl; thresh = 5.0; Vtemp = ain; eoc = SC_LOGIC_0; status = convert; } break; case convert: if (clk == 1) { cout << "stage 2: clk edge" << endl; thresh = thresh/2.0; if (Vtemp > thresh) { cout << "stage 3: Vtemp > thresh" << endl; dtemp[bit_cnt]= '1'; Vtemp = Vtemp- thresh; } else { dtemp[bit_cnt]= '0'; } if (bit_cnt > 0) { cout << "stage 4: bit_cnt > 0" << endl; bit_cnt = bit_cnt - 1; } else { cout << "last stage: conversion" << endl; dout = dtemp; status = input; wait(10, SC_US); eoc = SC_LOGIC_1; } } break; } // end switch } // end while } // end method conversion_logic ------------------------------------------------------------------------------------------------------------- SC-AMS models: which gives segmentation fault // Error message: stage 1: Read Input stage 3: Convert Input stage 1: Read Input stage 2 : start edge stage 3: Convert Input stage 4: clk edge !!! bit_cnt = 7 stage 1: Read Input stage 3: Convert Input stage 1: Read Input stage 3: Convert Input stage 4: clk edge !!! Segmentation fault // A2D.h #include <systemc-ams> #include <systemc> #include <stdio.h> using namespace std; //ref: VHDL-AMS Model of A2D converter given in System designer's guide to VHDL-AMS on page 287 SCA_TDF_MODULE (a2d_nbit) { //port declaration sca_tdf::sca_in<double> ain; // analog input pin sca_tdf::sca_de::sca_in<bool> clk; //clock signal sca_tdf::sca_de::sca_in<bool> start; //clock signal sca_tdf::sca_de::sca_out<sc_dt::sc_logic> eoc; //end of conversion pin sca_tdf::sca_de::sca_out<sc_dt::sc_lv<8> > dout; //digitalized output a2d_nbit(sc_core::sc_module_name nm, double Vmax_ = 5.0, double delay_ = 10.0e-6, int bit_range_ = 8, bool start_x_ = 0, bool clk_x_ = 0): ain("ain"), start("start"),clk("clk"), eoc("eoc"), dout("dout"), Vmax(Vmax_), delay(delay_), bit_range(bit_range_), start_x(start_x_), clk_x(clk_x_){} void set_attributes() { set_timestep(50, sc_core::SC_US); eoc.set_delay(1); } void initialize() { eoc.initialize(sc_dt::SC_LOGIC_0); } void processing(); private: double delay; // ADC conversion time double Vmax; int bit_range; bool clk_x; bool start_x; }; // A2D.cpp void a2d_nbit :: processing() { // double Vin = ain.read(); double thresh; //Threshold to test input voltage double Vtemp; //snapshot of input voltage when conversion starts sc_dt::sc_lv<8> dtemp; //temparary output data enum state {input, convert}; int bit_cnt; state status = input; switch(status) // ref: systemC state machine example in SystemC user guide on page 171 { case input : cout << "stage 1: Read Input" << endl; if((start == true) && (start_x == false)) //if (start == true) { cout << "stage 2 : start edge" << endl; bit_cnt = bit_range; thresh = Vmax; Vtemp = ain; eoc = sc_dt::sc_logic('0'); } case convert: cout << "stage 3: Convert Input" << endl; if ((clk == true) && (clk_x == false)) //if (clk == true) { cout << "stage 4: clk edge !!!" << endl; thresh = thresh/2.0; if (Vtemp > thresh) { dtemp[bit_cnt]= '1'; Vtemp = Vtemp - thresh; } else { dtemp[bit_cnt]= '0'; } if (bit_cnt > 0) { bit_cnt = bit_cnt - 1; cout << " bit_cnt = " << bit_cnt << endl; } else { dout = dtemp; eoc = sc_dt::sc_logic('1'); status = input; } break; } default: break; } // end switch start_x = start; clk_x = clk; } ---------------------------------------------------------------------------------------------------------------- // voltage source: dummy_source.h #include<systemc-ams> #include<systemc> #include<iostream.h> #include<fstream.h> using namespace std; SCA_TDF_MODULE (dummy_src) { // sca_tdf::sca_de::sca_out<double> output; sca_tdf:: sca_out<double> output; ifstream infile; double val; dummy_src(sc_core::sc_module_name): output("output"){} void set_attributes() { set_timestep(50, sc_core::SC_US); infile.open("datalog.txt"); } void processing () { if (infile >> val) { output.write(val); } else { output.write(0.0); } } }; ------------------------------------------------------------------------------------------------------------- // top_level_entity : interface.h #include<systemc-ams> #include<systemc> #include<A2D.h> //#include<SC_A2D.h> #include<dummy_source.h> using namespace std; using namespace sc_core; SC_MODULE (interface2) { // A2D_module a2d; a2d_nbit a2d; dummy_src input_vtg; sc_core::sc_clock clk1; sc_core::sc_clock start1; SC_CTOR(interface2) :in("in"), out("out"), a2d("a2d"), input_vtg("input_vtg"), clk1("clk1", 100, sc_core::SC_US, 0.5), start1("start1", 200, sc_core::SC_US, 0.5), eoc("eoc") { input_vtg.output(in); a2d.ain(in); a2d.start(start1.signal()); a2d.clk(clk1.signal()); a2d.eoc(eoc); a2d.dout(out); } public: // sc_core::sc_signal <double> in; sca_tdf::sca_signal<double> in; sc_core::sc_signal<sc_dt::sc_lv<8> > out; sc_core::sc_signal<sc_logic> eoc; }; // top_level_entity: interface2.cpp #include<systemc-ams.h> #include<systemc.h> #include<iomanip> #include<interface2.h> int sc_main(int argc, char* argv[]) { interface2 if2_dut("if2_dut"); sca_util :: sca_trace_file* atfs = sca_util :: sca_create_tabular_trace_file("if2.dat"); sca_util :: sca_trace(atfs, if2_dut.clk1, "\tCLK"); sca_util :: sca_trace(atfs, if2_dut.start1, "\tSTART"); sca_util :: sca_trace(atfs, if2_dut.in, "\tINPUT"); sca_util :: sca_trace(atfs, if2_dut.out, "\tOUTPUT"); sca_util :: sca_trace(atfs, if2_dut.eoc, "\tEOC"); sc_start(400, SC_US); sca_util :: sca_close_tabular_trace_file (atfs); return 0; } -------------------