IEC 61691-7:2025

IEC 61691-7 ®
Edition 2.0 2025-06
INTERNATIONAL
™
IEEE Std 1666
STANDARD
Behavioural languages –
Part 7: SystemC® Language Reference Manual
ICS 25.040.01; 35.060  ISBN 978-2-8327-0467-7

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IEEE Std 1666™‐2023
Contents
1. Overview. 23
1.1 Scope. 23
1.2 Purpose. 23
1.3 Word usage . 23
1.4 Subsets . 24
1.5 Relationship with C++ standard . 24
1.6 Guidance for readers . 24
2. Normative references. 26
3. Terminology and conventions used in this standard. 27
3.1 Terminology. 27
3.1.1 Shall, should, may, can . 27
3.1.2 Implementation, application . 27
3.1.3 Call, called from, derived from. 27
3.1.4 Specific technical terms . 27
3.2 Syntactical conventions . 29
3.2.1 Implementation-defined. 29
3.2.2 Disabled . 29
3.2.3 Ellipsis (.). 29
3.2.4 Class names. 29
3.2.5 Embolded text . 30
3.3 Semantic conventions . 30
3.3.1 Class definitions and the inheritance hierarchy . 30
3.3.2 Function definitions and side-effects. 30
3.3.3 Functions that use const char* as parameter. 30
3.3.4 Functions whose return type is a reference or a pointer . 31
3.3.5 Namespaces and internal naming . 33
3.3.6 Non-compliant applications and errors. 33
3.4 Notes and examples . 33
4. Elaboration and simulation semantics . 34
4.1 Overview. 34
4.2 Elaboration. 34
4.2.1 Overview. 34
4.2.2 Instantiation . 35
4.2.3 Process macros. 36
4.2.4 Port binding and export binding . 36
4.2.5 Setting the time resolution . 37
4.3 Simulation. 38
4.3.1 Overview. 38
4.3.2 The scheduling algorithm . 38
4.3.3 Initialization, cycles, pauses,and suspension in the scheduling algorithm . 41
4.4 Running elaboration and simulation . 42
4.4.1 Overview. 42
4.4.2 Function declarations. 42
4.4.3 sc_elab_and_sim.43
4.4.4 sc_argc and sc_argv . 43
Published by IEC under licence from IEEE. © 2023 IEEE. All rights reserved.

IEEE Std 1666™‐2023
4.4.5 Running under application control using functions sc_main and sc_start. 44
4.4.6 Running under control of the kernel . 46
4.5 Elaboration and simulation callbacks . 46
4.5.1 Overview. 46
4.5.2 before_end_of_elaboration . 47
4.5.3 end_of_elaboration . 48
4.5.4 start_of_simulation .49
4.5.5 end_of_simulation . 50
4.6 Other functions related to the scheduler . 50
4.6.1 Function declarations. 50
4.6.2 sc_pause . 52
4.6.3 sc_suspend_all, sc_unsuspend_all, sc_unsuspendable, and sc_suspendable . 53
4.6.4 sc_stop, sc_set_stop_mode, and sc_get_stop_mode . 53
4.6.5 sc_time_stamp . 54
4.6.6 sc_delta_count and sc_delta_count_at_current_time . 55
4.6.7 sc_is_running . 55
4.6.8 Functions to detect pending activity . 56
4.6.9 sc_get_status . 57
4.6.10 sc_stage_callback_if .58
4.6.11 sc_register_stage_callback . 60
4.6.12 sc_unregister_stage_callback . 60
4.6.13 Callbacks execution .60
5. Core language class definitions . 61
5.1 Class header files . 61
5.1.1 Overview. 61
5.1.2 #include "systemc".61
5.1.3 #include "systemc.h". 61
5.2 sc_module . 62
5.2.1 Description. 62
5.2.2 Class definition . 62
5.2.3 Constraints on usage . 65
5.2.4 kind . 65
5.2.5 SC_MODULE . 65
5.2.6 Constructors . 66
5.2.7 SC_CTOR. 66
5.2.8 SC_METHOD, SC_THREAD, SC_CTHREAD. 67
5.2.9 SC_NAMED . 68
5.2.10 Method process . 68
5.2.11 Thread and clocked thread processes. 69
5.2.12 Clocked thread processes. 70
5.2.13 reset_signal_is and async_reset_signal_is . 72
5.2.14 sensitive . 73
5.2.15 dont_initialize . 74
5.2.16 set_stack_size. 75
5.2.17 next_trigger. 75
5.2.18 wait. 77
5.2.19 Positional port binding.78
5.2.20 before_end_of_elaboration, end_of_elaboration, start_of_simulation,
end_of_simulation . 80
5.2.21 get_child_objects and get_child_events . 80
5.2.22 sc_gen_unique_name. 81
5.2.23 sc_behavior and sc_channel. 81
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IEEE Std 1666™‐2023
5.3 sc_module_name . 82
5.3.1 Description. 82
5.3.2 Class definition . 82
5.3.3 Constraints on usage . 83
5.3.4 Module hierarchy.83
5.3.5 Member functions . 84
5.4 sc_sensitive† . 85
5.4.1 Description. 85
5.4.2 Class definition . 85
5.4.3 Constraints on usage . 85
5.4.4 operator<<. 85
5.5 sc_spawn_options and sc_spawn. 86
5.5.1 Description. 86
5.5.2 Class definition . 86
5.5.3 Constraints on usage . 88
5.5.4 Constructors . 88
5.5.5 Member functions . 88
5.5.6 sc_spawn. 89
5.5.7 SC_FORK and SC_JOIN. 92
5.6 sc_process_handle . 93
5.6.1 Description. 93
5.6.2 Class definition . 93
5.6.3 Constraints on usage . 95
5.6.4 Constructors . 95
5.6.5 Member functions . 95
5.6.6 Member functions for process control . 98
5.6.7 sc_get_current_process_handle . 114
5.6.8 sc_is_unwinding . 115
5.7 sc_event_finder and sc_event_finder_t . 116
5.7.1 Description. 116
5.7.2 Class definition . 116
5.7.3 Constraints on usage . 116
5.8 sc_event_and_list and sc_event_or_list. 118
5.8.1 Description. 118
5.8.2 Class definition . 118
5.8.3 Constraints and usage . 119
5.8.4 Constructors, destructor, assignment . 119
5.8.5 Member functions and operators . 119

5.9 sc_event_and_expr† and sc_event_or_expr†. 121
5.9.1 Description. 121
5.9.2 Class definition . 121
5.9.3 Constraints on usage . 122
5.9.4 Operators. 122
5.10 sc_event . 123
5.10.1 Description. 123
5.10.2 Class definition . 123
5.10.3 Constraints on usage . 124
5.10.4 Constructors, destructor, and event naming. 124
5.10.5 Functions for naming and hierarchy traversal . 125
5.10.6 notify and cancel. 126
5.10.7 Event lists. 127
5.10.8 None event . 127
5.10.9 Multiple event notifications . 127
5.11 sc_time . 128
Published by IEC under licence from IEEE. © 2023 IEEE. All rights reserved.

IEEE Std 1666™‐2023
5.11.1 Description. 128
5.11.2 Class definition . 128
5.11.3 Constructors . 129
5.11.4 Functions and operators . 130
5.11.5 Time resolution . 130
5.11.6 sc_max_time . 131
5.11.7 SC_ZERO_TIME . 131
5.12 sc_port. 131
5.12.1 Description. 131
5.12.2 Class definition . 131
5.12.3 Template parameters. 133
5.12.4 Constraints on usage . 134
5.12.5 Constructors . 135
5.12.6 kind . 135
5.12.7 Named port binding . 135
5.12.8 Member functions for bound ports and port-to-port binding. 136
5.12.9 before_end_of_elaboration, end_of_elaboration, start_of_simulation,
end_of_simulation . 140
5.13 sc_export. 140
5.13.1 Description. 140
5.13.2 Class definition . 140
5.13.3 Template parameters. 141
5.13.4 Constraints on usage . 141
5.13.5 Constructors . 142
5.13.6 kind . 142
5.13.7 Export binding . 142
5.13.8 Member functions for bound exports and export-to-export binding . 143
5.13.9 before_end_of_elaboration, end_of_elaboration, start_of_simulation,
end_of_simulation . 144
5.14 sc_interface . 144
5.14.1 Description. 144
5.14.2 Class definition . 145
5.14.3 Constraints on usage . 145
5.14.4 register_port . 145
5.14.5 default_event. 146
5.15 sc_prim_channel . 147
5.15.1 Description. 147
5.15.2 Class definition . 147
5.15.3 Constraints on usage . 148
5.15.4 Constructors, destructor, and hierarchical names . 148
5.15.5 kind . 149
5.15.6 request_update and update. 149
5.15.7 async_attach_suspending and async_detach_suspending .150
5.15.8 next_trigger and wait . 150
5.15.9 before_end_of_elaboration, end_of_elaboration, start_of_simulation,
end_of_simulation . 151
5.16 sc_object . 152
5.16.1 Description. 152
5.16.2 Class definition . 152
5.16.3 Constraints on usage . 153
5.16.4 Constructors and destructor . 153
5.16.5 name, basename, and kind . 154
5.16.6 print and dump . 155
5.16.7 Functions for object hierarchy traversal . 155
Published by IEC under licence from IEEE. © 2023 IEEE. All rights reserved.

IEEE Std 1666™‐2023
5.16.8 Member functions for attributes . 157
5.16.9 get_hierarchy_scope . 158
5.17 Hierarchical naming of objects and events . 158
5.17.1 Overview. 158
5.17.2 sc_hierarchical_name_exists . 159
5.17.3 sc_register_hierarchical_name, sc_unregister_hierarchical_name. 160
5.18 sc_attr_base. 160
5.18.1 Description. 160
5.18.2 Class definition . 160
5.18.3 Member functions . 161
5.19 sc_attribute. 161
5.19.1 Description. 161
5.19.2 Class definition . 161
5.19.3 Template parameters. 161
5.19.4 Member functions and data members. 161
5.20 sc_attr_cltn. 162
5.20.1 Description. 162
5.20.2 Class definition . 162
5.20.3 Constraints on usage . 162
5.20.4 Iterators . 162
5.21 sc_hierarchy_scope. 163
5.21.1 Description. 163
5.21.2 Class definition . 163
5.21.3 Constraints on usage . 163
5.21.4 Constructor. 164
5.21.5 get_root . 164
6. Predefined channel class definitions. 165
6.1 sc_signal_in_if . 165
6.1.1 Description. 165
6.1.2 Class definition . 165
6.1.3 Member functions . 165
6.2 sc_signal_in_if and sc_signal_in_if. 166
6.2.1 Description. 166
6.2.2 Class definition . 166
6.2.3 Member functions . 167
6.3 sc_signal_inout_if. 167
6.3.1 Description. 167
6.3.2 Class definition . 167
6.3.3 Member functions . 168
6.4 sc_signal. 168
6.4.1 Description. 168
6.4.2 Class definition . 169
6.4.3 Template parameter T. 169
6.4.4 Reading and writing signals. 170
6.4.5 Constructors . 171
6.4.6 register_port . 171
6.4.7 Member functions for reading . 172
6.4.8 Member functions for writing. 172
6.4.9 Member functions for events . 172
6.4.10 Diagnostic member functions . 173
6.4.11 operator<<. 173
6.5 sc_signal and sc_signal . 174
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IEEE Std 1666™‐2023
6.5.1 Description. 174
6.5.2 Class definition . 174
6.5.3 Member functions . 176
6.6 sc_buffer . 177
6.6.1 Description. 177
6.6.2 Class definition . 177
6.6.3 Constructors . 177
6.6.4 Member functions . 178
6.7 sc_clock . 179
6.7.1 Description. 179
6.7.2 Class definition . 179
6.7.3 Characteristic properties . 180
6.7.4 Constructors . 180
6.7.5 write . 180
6.7.6 Diagnostic member functions . 181
6.7.7 before_end_of_elaboration . 181
6.7.8 sc_in_clk . 181
6.8 sc_in . 181
6.8.1 Description. 181
6.8.2 Class definition . 181
6.8.3 Member functions . 182
6.8.4 sc_trace . 183
6.8.5 end_of_elaboration . 183
6.9 sc_in and sc_in. 183
6.9.1 Description. 183
6.9.2 Class definition . 183
6.9.3 Member functions . 185
6.10 sc_inout. 186
6.10.1 Description. 186
6.10.2 Class definition . 186
6.10.3 Member functions . 187
6.10.4 initialize . 187
6.10.5 sc_trace . 187
6.10.6 end_of_elaboration . 188
6.10.7 Binding. 188
6.11 sc_inout and sc_inout . 188
6.11.1 Description. 188
6.11.2 Class definition . 188
6.11.3 Member functions . 190
6.12 sc_out . 190
6.12.1 Description. 190
6.12.2 Class definition . 190
6.12.3 Member functions . 191
6.13 sc_signal_resolved . 191
6.13.1 Description. 191
6.13.2 Class definition . 191
6.13.3 Constructors . 192
6.13.4 Resolution semantics . 192
6.13.5 Member functions . 193
6.14 sc_in_resolved .
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