test.cpp revision 12855:588919e0e4aa 
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20/*****************************************************************************
21
22  test.cpp --
23
24  Original Author: Martin Janssen, Synopsys, Inc., 2002-02-15
25
26 *****************************************************************************/
27
28/*****************************************************************************
29
30  MODIFICATION LOG - modifiers, enter your name, affiliation, date and
31  changes you are making here.
32
33      Name, Affiliation, Date:
34  Description of Modification:
35
36 *****************************************************************************/
37
38/*
39Hello,
40
41sorry for asking again about the sc_start/sc_cycle problem but...
42
43The following program causes trouble (SystemC V2.0b2):
44*/
45
46#include "systemc.h"
47
48SC_MODULE(createpulse)
49 {
50  public:
51  sc_in_clk i_clk;
52  private:
53  int trigger1,trigger2;
54  void pulse()
55   {
56    while(true)
57     {
58      wait();
59      cout << sc_time_stamp() << ": trigger1 : " <<trigger1++ << endl;
60      wait(1,SC_NS);
61      cout << sc_time_stamp() << ": trigger2 : " <<trigger2++ << endl;
62     }
63   }
64  public:
65  SC_CTOR(createpulse)
66   {
67    SC_THREAD(pulse);
68    sensitive << i_clk.pos();
69    trigger1 = 0;
70    trigger2 = 0;
71   }
72 };
73
74// createpulse dut("testpulse");
75
76int sc_main(int argc, char *argv[])
77 {
78  int i;
79  sc_trace_file *tf;
80  sc_signal<bool> clk1;
81
82  sc_set_time_resolution(1,SC_NS);
83  sc_set_default_time_unit(1,SC_NS);
84
85  // sc_clock dummy( "dummy", 2, SC_NS );
86
87  createpulse dut("testpulse");
88
89  dut.i_clk(clk1);      // see other posting
90
91  tf=sc_create_vcd_trace_file("vcdtrace");
92  sc_trace(tf,clk1,"clock");
93
94  // sc_initialize();      // comment out for sc_start version
95  for(i=0;i<10;i++)
96   {
97    clk1=0;
98    // sc_cycle(5,SC_NS);  // change to sc_start
99    sc_start( 5, SC_NS );
100    clk1=1;
101    // sc_cycle(5,SC_NS);  // change to sc_start
102    sc_start( 5, SC_NS );
103   }
104
105  cout << "finishing at " << sc_time_stamp() << endl;
106  sc_close_vcd_trace_file(tf);
107
108  return(EXIT_SUCCESS);
109 }
110
111/*
112With this programm, the clk1 is generated as can be seen in the trace file.
113But the pulse procedure gets stuck in the second wait function. With SystemC
114V1.x, this worked with replacing sc_cycle with sc_start (and removing the
115sc_initialize), however calling sc_start multiple was an undocumented feature
116and it doesnt work in V2.0b2 (no clk is generated).
117I know that this problem can be solved by creating an own clock generation
118module using wait()s and just a single sc_start in sc_main, but IMHO
119sometimes it is desirable to do it the way shown above. So is this possible
120with SystemC V2.0 ?
121
122Regards, Sven Heithecker
123
124--
125Sven Heithecker                            IDA, Hans-Sommer-Str. 66
126Technical University of Braunschweig       38106 Braunschweig
127Tel. +49-(0)531-391-3751(voice)/4587(fax)  Germany
128http://www.ida.ing.tu-bs.de/~svenh         heithecker@ida.ing.tu-bs.de
129*/
130