IEC 61691-7:2009

Behavioural languages - Part 7: SystemC R Language Reference Manual

IEC 61691-7:2009(E) defines SystemC®1 as an ANSI standard C++ class library for system and hardware design. The specific purpose is to provide a precise and complete defination of the System C class library so that a System C implementation can be developed.

General Information

• Status: Published
• Publication Date: 13-Dec-2009
• ICS: 25.040.01 - Industrial automation systems in general
• ICS: 35.060 - Languages used in information technology
• Technical Committee: TC 91 - Electronics assembly technology
• Drafting Committee: WG 13 - TC 91/WG 13
• Current Stage: PPUB - Publication issued
• Start Date: 14-Dec-2009
• Completion Date: 15-Jan-2010

Relations

• Revised: IEC 61691-7:2025 - Behavioural languages - Part 7: SystemC® Language Reference Manual
• Effective Date: 14-Mar-2025

Overview

IEC 61691-7:2009 - Behavioural languages, Part 7: SystemC Language Reference Manual (also published as IEEE Std 1666) defines SystemC as an ANSI C++ class library for system- and hardware-level design. The standard provides a precise, normative description of the SystemC class library so that conformant SystemC implementations, simulators and tools can be developed and interoperated consistently.

Key topics and technical requirements

The standard specifies the language reference and runtime semantics for SystemC, including:

• Elaboration and simulation semantics - formal definitions of instantiation, binding, scheduler behavior, simulation cycles and callbacks.
• Core language classes and headers - normative definitions for module and kernel primitives (for example sc_module, sc_module_name, and the prescribed header usage).
• Process and concurrency models - method, thread and clocked-thread processes, process macros (SC_METHOD, SC_THREAD, etc.), creation and control of processes.
• Event and timing primitives - event classes and lists (sc_event, sc_event_and_list, sc_event_or_list), notification and cancellation semantics, and time representation (sc_time).
• Sensitivity and triggering - mechanisms for expressing process sensitivity and next-trigger semantics.
• Process control and handles - spawning, joining, handles and utilities (sc_spawn, sc_process_handle).
• Kernel control and callbacks - lifecycle callbacks (before_end_of_elaboration, end_of_elaboration, start_of_simulation, end_of_simulation), sc_start/sc_stop and related scheduler controls.
• Conformance and C++ relationship - guidance on relationship to C++, implementation-defined behaviors, naming conventions and constraints.

The standard requires a precise and complete definition of the class library API and the simulator kernel behavior so that compliant implementations behave predictably across tools.

Practical applications

IEC 61691-7 is essential for:

• Implementing SystemC simulators and runtimes used in EDA and tooling.
• Building system-level models, virtual platforms, transaction-level modeling (TLM) components, and ESL (electronic system-level) libraries.
• Enabling hardware/software co-design, architectural exploration, and early software development on virtual prototypes.
• Creating verification environments that rely on consistent scheduling, event and time semantics.

Who should use this standard

• EDA tool vendors and simulator implementers
• SoC architects and system designers using SystemC for modeling
• Verification engineers developing testbenches in SystemC
• Academic researchers and educators in system-level design
• Software teams building SystemC-based virtual platforms or TLM models

Related standards

• IEEE Std 1666-2005 (same normative content) - frequently referenced alongside IEC 61691-7 for SystemC conformance and tool interoperability.

Keywords: IEC 61691-7, SystemC, SystemC Language Reference Manual, IEEE Std 1666, system-level modeling, C++ class library, sc_module, sc_event, sc_time, simulation semantics.

Standards Content (Sample)

IEC 61691-7
Edition 1.0 2009-12
™
IEEE Std 1666
INTERNATIONAL
STANDARD
Behavioural languages – ®
Part 7: SystemC Language Reference Manual

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IEC 61691-7
Edition 1.0 2009-12
™
IEEE Std 1666
INTERNATIONAL
STANDARD
Behavioural languages – ®
Part 7: SystemC Language Reference Manual
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
PRICE CODE
XH
ICS 25.040, 35.060 ISBN 978-0-7381-6284-3

– i – IEC 61691-7:2009(E)
IEEE Std 1666-2005(E)
CONTENTS
Foreword.xi
IEEE Introduction .xvi
1. Overview. 1
1.1 Scope. 1
1.2 Purpose. 1
1.3 Subsets . 1
1.4 Relationship with C++. 1
1.5 Guidance for readers. 2
2. References. 3
3. Terminology and conventions used in this standard. 4
3.1 Terminology. 4
3.1.1 Shall, should, may, can. 4
3.1.2 Implementation, application. 4
3.1.3 Call, called from, derived from . 4
3.1.4 Specific technical terms . 4
3.2 Syntactical conventions . 6
3.2.1 Implementation-defined. 6
3.2.2 Disabled . 6
3.2.3 Ellipsis (.). 6
3.2.4 Class names. 6
3.2.5 Embolded text .7
3.3 Semantic conventions . 7
3.3.1 Class definitions and the inheritance hierarchy . 7
3.3.2 Function definitions and side-effects . 7
3.3.3 Functions whose return type is a reference or a pointer. 7
3.3.4 Namespaces and internal naming. 9
3.3.5 Non-compliant applications and errors . 9
3.4 Notes and examples . 10
4. Elaboration and simulation semantics . 11
4.1 Elaboration. 11
4.1.1 Instantiation . 11
4.1.2 Process macros. 13
4.1.3 Port binding and export binding . 13
4.1.4 Setting the time resolution . 14
4.2 Simulation. 14
4.2.1 The scheduling algorithm . 15
4.2.2 Cycles in the scheduling algorithm. 17
4.3 Running elaboration and simulation . 18
4.3.1 Function declarations. 18
4.3.2 Function sc_elab_and_sim. 18
4.3.3 Functions sc_argc and sc_argv . 19
4.3.4 Running under application control using functions sc_main and sc_start. 19
4.3.5 Running under control of the kernel . 20
4.4 Elaboration and simulation callbacks . 20
4.4.1 before_end_of_elaboration . 21
4.4.2 end_of_elaboration . 22
4.4.3 start_of_simulation . 23
Published by IEC under licence from IEEE. © 2005 IEEE. All rights reserved.

IEEE Std 1666-2005(E)
4.4.4 end_of_simulation . 23
4.5 Other functions related to the scheduler . 24
4.5.1 Function declarations . 24
4.5.2 Function sc_stop, sc_set_stop_mode, and sc_get_stop_mode. 24
4.5.3 Function sc_time_stamp. 25
4.5.4 Function sc_delta_count. 26
4.5.5 Function sc_is_running . 26
5. Core language class definitions . 27
5.1 Class header files . 27
5.1.1 #include "systemc". 27
5.1.2 #include "systemc.h". 27
5.2 sc_module . 29
5.2.1 Description . 29
5.2.2 Class definition.29
5.2.3 Constraints on usage. 31
5.2.4 kind. 31
5.2.5 SC_MODULE. 31
5.2.6 Constructors .32
5.2.7 SC_CTOR . 32
5.2.8 SC_HAS_PROCESS. 33
5.2.9 SC_METHOD, SC_THREAD, SC_CTHREAD. 33
5.2.10 Method process . 34
5.2.11 Thread and clocked thread processes. 35
5.2.12 Clocked thread processes and reset_signal_is. 36
5.2.13 sensitive. 37
5.2.14 dont_initialize. 38
5.2.15 set_stack_size. 39
5.2.16 next_trigger . 39
5.2.17 wait. 41
5.2.18 Positional port binding . 43
5.2.19 before_end_of_elaboration, end_of_elaboration, start_of_simulation,
end_of_simulation. 44
5.2.20 get_child_objects. 45
5.2.21 sc_gen_unique_name . 45
5.2.22 sc_behavior and sc_channel. 46
5.3 sc_module_name . 47
5.3.1 Description. 47
5.3.2 Class definition . 47
5.3.3 Constraints on usage . 47
5.3.4 Module hierarchy . 48
5.3.5 Member functions . 48
5.4 sc_sensitive† . 50
5.4.1 Description. 50
5.4.2 Class definition . 50
5.4.3 Constraints on usage . 50
5.4.4 operator<<. 50
5.5 sc_spawn_options and sc_spawn. 52
5.5.1 Description. 52
5.5.2 Class definition . 52
5.5.3 Constraints on usage . 53
5.5.4 Constructors .53
5.5.5 Member functions . 53
Published by IEC under licence from IEEE. © 2005 IEEE. All rights reserved.

– iii – IEC 61691-7:2009(E)
IEEE Std 1666-2005(E)
5.5.6 sc_spawn . 54
5.5.7 SC_FORK and SC_JOIN. 56
5.6 sc_process_handle . 58
5.6.1 Description . 58
5.6.2 Class definition.58
5.6.3 Constraints on usage . 59
5.6.4 Constructors .59
5.6.5 Member functions . 59
5.6.6 sc_get_current_process_handle. 61
5.7 sc_event_finder and sc_event_finder_t . 62
5.7.1 Description . 62
5.7.2 Class definition.62
5.7.3 Constraints on usage. 62

5.8 sc_event_and_list† and sc_event_or_list† . 65
5.8.1 Description . 65
5.8.2 Class definition.65
5.8.3 Constraints on usage. 65
5.8.4 Event lists . 65
5.9 sc_event . 66
5.9.1 Description . 66
5.9.2 Class definition.66
5.9.3 Constraints on usage. 66
5.9.4 notify and cancel . 66
5.9.5 Event lists . 67
5.9.6 Multiple event notifications . 67
5.10 sc_time . 68
5.10.1 Description . 68
5.10.2 Class definition. 68
5.10.3 Time resolution . 69
5.10.4 Functions and operators . 69
5.10.5 SC_ZERO_TIME. 69
5.11 sc_port. 71
5.11.1 Description. 71
5.11.2 Class definition .71
5.11.3 Template parameters. 72
5.11.4 Constraints on usage . 73
5.11.5 Constructors . 74
5.11.6 kind . 74
5.11.7 Named port binding . 74
5.11.8 Member functions for bound ports and port-to-port binding. 75
5.11.9 before_end_of_elaboration, end_of_elaboration, start_of_simulation,
end_of_simulation. 79
5.12 sc_export. 80
5.12.1 Description . 80
5.12.2 Class definition. 80
5.12.3 Template parameters . 81
5.12.4 Constraints on usage. 81
5.12.5 Constructors . 81
5.12.6 kind. 81
5.12.7 Export binding.82
5.12.8 Member functions for bound exports and export-to-export binding. 83
5.12.9 before_end_of_elaboration, end_of_elaboration, start_of_simulation,
end_of_simulation. 84
Published by IEC under licence from IEEE. © 2005 IEEE. All rights reserved.

IEEE Std 1666-2005(E)
5.13 sc_interface . 85
5.13.1 Description . 85
5.13.2 Class definition. 85
5.13.3 Constraints on usage. 85
5.13.4 register_port . 86
5.13.5 default_event . 86
5.14 sc_prim_channel . 88
5.14.1 Description . 88
5.14.2 Class definition. 88
5.14.3 Constraints on usage . 89
5.14.4 Constructors . 89
5.14.5 kind. 89
5.14.6 request_update and update . 89
5.14.7 next_trigger and wait. 90
5.14.8 before_end_of_elaboration, end_of_elaboration, start_of_simulation,
end_of_simulation. 90
5.15 sc_object . 92
5.15.1 Description . 92
5.15.2 Class definition. 92
5.15.3 Constraints on usage. 93
5.15.4 Constructors and hierarchical names. 93
5.15.5 name, basename, and kind. 94
5.15.6 print and dump . 95
5.15.7 Functions for object hierarchy traversal. 95
5.15.8 Member functions for attributes. 97
5.16 sc_attr_base. 99
5.16.1 Description. 99
5.16.2 Class definition .99
5.16.3 Member functions . 99
5.17 sc_attribute. 100
5.17.1 Description . 100
5.17.2 Class definition. 100
5.17.3 Template parameters. 100
5.17.4 Member functions and data members. 100
5.18 sc_attr_cltn. 101
5.18.1 Description .101
5.18.2 Class definition. 101
5.18.3 Constraints on usage. 101
5.18.4 Iterators. 101
6. Predefined channel class definitions. 103
6.1 sc_signal_in_if . 103
6.1.1 Description . 103
6.1.2 Class definition. 103
6.1.3 Member functions . 103
6.2 sc_signal_in_if and sc_signal_in_if. 104
6.2.1 Description . 104
6.2.2 Class definition. 104
6.2.3 Member functions . 105
6.3 sc_signal_inout_if. 106
6.3.1 Description . 106
6.3.2 Class definition. 106
6.3.3 write. 106
Published by IEC under licence from IEEE. © 2005 IEEE. All rights reserved.

– v – IEC 61691-7:2009(E)
IEEE Std 1666-2005(E)
6.4 sc_signal. 107
6.4.1 Description. 107
6.4.2 Class definition . 107
6.4.3 Template parameter T . 108
6.4.4 Reading and writing signals. 108
6.4.5 Constructors . 109
6.4.6 register_port . 109
6.4.7 Member functions for reading . 109
6.4.8 Member functions for writing. 110
6.4.9 Member functions for events . 110
6.4.10 Diagnostic member functions . 110
6.4.11 operator<<.111
6.5 sc_signal and sc_signal. 113
6.5.1 Description . 113
6.5.2 Class definition. 113
6.5.3 Member functions . 114
6.6 sc_buffer . 116
6.6.1 Description. 116
6.6.2 Class definition . 116
6.6.3 Constructors . 116
6.6.4 Member functions . 117
6.7 sc_clock . 119
6.7.1 Description. 119
6.7.2 Class definition . 119
6.7.3 Characteristic properties . 120
6.7.4 Constructors . 120
6.7.5 write . 120
6.7.6 Diagnostic member functions . 120
6.7.7 before_end_of_elaboration . 121
6.7.8 sc_in_clk .121
6.8 sc_in . 122
6.8.1 Description. 122
6.8.2 Class definition . 122
6.8.3 Member functions . 123
6.8.4 Function sc_trace . 123
6.8.5 end_of_elaboration . 123
6.9 sc_in and sc_in. 124
6.9.1 Description . 124
6.9.2 Class definition. 124
6.9.3 Member functions . 126
6.10 sc_inout. 127
6.10.1 Description.127
6.10.2 Class definition . 127
6.10.3 Member functions . 128
6.10.4 initialize. 128
6.10.5 Function sc_trace . 128
6.10.6 end_of_elaboration . 129
6.10.7 Binding. 129
6.11 sc_inout and sc_inout . 130
6.11.1 Description.130
6.11.2 Class definition . 130
6.11.3 Member functions . 132
6.12 sc_out . 133
6.12.1 Description .133
Published by IEC under licence from IEEE. © 2005 IEEE. All rights reserved.

IEEE Std 1666-2005(E)
6.12.2 Class definition. 133
6.12.3 Member functions . 133
6.13 sc_signal_resolved . 134
6.13.1 Description.134
6.13.2 Class definition . 134
6.13.3 Constructors . 134
6.13.4 Resolution semantics . 135
6.13.5 Member functions . 136
6.14 sc_in_resolved . 137
6.14.1 Description.137
6.14.2 Class definition . 137
6.14.3 Member functions . 137
6.15 sc_inout_resolved . 138
6.15.1 Description .138
6.15.2 Class definition. 138
6.15.3 Member functions . 138
6.16 sc_out_resolved . 139
6.16.1 Description .139
6.16.2 Class definition. 139
6.16.3 Member functions. 139
6.17 sc_signal_rv . 140
6.17.1 Description.140
6.17.2 Class definition . 140
6.17.3 Semantics and member functions . 140
6.18 sc_in_rv. 142
6.18.1 Description.142
6.18.2 Class definition . 142
6.18.3 Member functions . 142
6.19 sc_inout_rv. 143
6.19.1 Description .143
6.19.2 Class definition. 143
6.19.3 Member functions . 143
6.20 sc_out_rv. 145
6.20.1 Description .145
6.20.2 Class definition. 145
6.20.3 Member functions . 145
6.21 sc_fifo_in_if. 146
6.21.1 Description .146
6.21.2 Class definition. 146
6.21.3 Member functions . 146
6.22 sc_fifo_out_if. 148
6.22.1 Description.148
6.22.2 Class definition . 148
6.22.3 Member functions . 148
6.23 sc_fifo . 150
6.23.1 Description .150
6.23.2 Class definition. 150
6.23.3 Template parameter T . 151
6.23.4 Constructors . 151
6.23.5 register_port .152
6.23.6 Member functions for reading. 152
6.23.7 Member functions for writing . 152
6.23.8 The update phase.
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