Jump to content

maehne

Members
  • Content Count

    254
  • Joined

  • Last visited

  • Days Won

    31

Everything posted by maehne

  1. @plafratt: It would be very helpful if you could provide more detailed information to reproduce your observation as suggested by @Roman Popov. With what version of g++ running on which platform have you observed the warning. A small self-contained code example demonstrating the issue would help us to reproduce the issue on our side so that we can forward the issue with enough information to the SystemC Language Working Group for fixing.
  2. Thanks @Asdruv for reporting this bug! I have forwarded your report to the LWG. Best regards, Torsten Maehne
  3. sc_core::sc_in<T> only allows binding of a single sc_core::sc_signal<T> (cf. to IEEE Std 1666-2011, clause 6.8). However, you may use for in_B a sc_core::sc_port<sc_core::sc_signal_in_if<T>, 3, SC_ONE_OR_MORE_BOUND> (cf. to IEEE Std 1666-2011, clause 5.12) that will accept binding of exactly three signals. The implementation of the OR relation of the three signals can be then handled inside an SC_METHOD of objB. To access the three different signal from in_B, you can use the operator[] implemented by the sc_port. By the way, you may also specify a different number of channels to be bound and also a different port binding policy.
  4. If you don't use the member functions added that were added for convenience to `sc_in`, `sc_out`, and `sc_inout` to, e.g., call `read()`, `write()`, and the event member functions via the `.` operator than via the corresponding member function in the interface accessed via the `->` operator, you might be able to avoid entirely the derivation of new port classes. Instead, you could simply use a template alias, which was introduced with C++'11: template<typename T> using sc_in_opt = sc_core::sc_port<sc_signal_in_if<T>, 1, SC_ZERO_OR_MORE_BOUND>; template<typename T> using sc_inout_opt = sc_core::sc_port<sc_signal_inout_if<T>, 1, SC_ZERO_OR_MORE_BOUND>; template<typename T> using sc_out_opt = sc_core::sc_port<sc_signal_inout_if<T>, 1, SC_ZERO_OR_MORE_BOUND>; If you want to also provide all member functions of `sc_in`, `sc_out`, and `sc_inout`, you will have to derive from the `sc_port` class and implement the full interface as defined in IEEE Std 1666-2011.
  5. This output does not hint for any problem. What output do you expect from your alu model? You need to implement explicitly any debug output in your SystemC model using, e.g., the SC_REPORT_* macros. Tracing of signal using the sc_trace() mechanism won't cause any additional output on the console either. If you expect some output, you will have to share the code of a minimal working example exposing your problem. Your CMakeLists.txt looks mostly fine. However, it contains several unnecessary lines. After finding SystemC using find_package, you only need to make sure that your executable target is linked against the SystemC::systemc target using the target_link_libraries(alu SystemC::systemc) call. CMake retrieves from this target automatically any necessary compiler flags, preprocessor definitions, include paths, and library paths, which previously needed to be set up by hand. So, your minimal CMake file could look something like: cmake_minimum_required(VERSION 3.1) project(alu) find_package(SystemCLanguage CONFIG REQUIRED) # # Setting the C++ standard from the SystemC_CXX_STANDARD variable may be still # # needed to compile without. So, in case of errors, try to uncomment the # # following two set (...) commands. The experimental CMake-based build system # # of the SystemC PoC implementation needs some updates to simplify further # # building SystemC application using CMake by using features introduced in # # CMake >3.11, which enable specifying even better the build and usage requirements # # of a library or executable. # set (CMAKE_CXX_STANDARD ${SystemC_CXX_STANDARD} CACHE STRING "C++ standard to build all targets. Supported values are 98, 11, and 14.") # set (CMAKE_CXX_STANDARD_REQUIRED ${SystemC_CXX_STANDARD_REQUIRED} CACHE BOOL # "The with CMAKE_CXX_STANDARD selected C++ standard is a requirement.") add_executable(alu main.cpp testbench.cpp) target_link_libraries(alu SystemC::systemc) The Section 4 of cmake/INSTALL_USING_CMAKE file contains some more hints.
  6. Your calls to the configure script don't include the option --prefix to specify the destination directory for installation. This is strongly recommended as the SystemC installation layout does not match well with the standard Unix directory layout for a conflict-free installation. Personally, I prefer to install SystemC on Unix-like platforms to /opt/systemc-2.3.3 (or similar). After make install, you can make sure that the include and lib-* directory below the prefix contains the necessary files. When building against this SystemC version, you will have to pass the proper include and linker flags. I recommend that you read the INSTALL and RELEASENOTES files, which are part of the SystemC PoC implementation. You may also consider to use the experimental CMake-based build system instead of the autotools.
  7. Before implementing your own ports and attempting to modify the SystemC code, you should first get familiar with the basic concepts and capabilities of SystemC. I suggest that you read a good introductory text to SystemC, e.g., "SystemC from the Ground Up" by David Black et al. That said, your requirement description seems to indicate that you could achieve the wanted functionality by using simply the standard SystemC ports and signals: One instance of sc_core::sc_out<T> in some module, which drives the global signal of type sc_core::sc_signal<T> that is bound to it during elaboration. And n port instances of sc_core::sc_in<T> bound to the same signal. You can then make some SC_METHOD or SC_THREAD in the module which instantiates one or several of this in ports to be sensitive to changes on this/these ports.
  8. The SystemC libraries and their associated headers are usually not installed into the standard locations (/usr/lib/ and /usr/include/), where they would be found automatically by the compiler and linker. Instead, they are typically installed into their own directory hierarchy, e.g., below /opt/systemc-2.3.1/. Therefore, you need to indicate their location explicitly to the compiler and linker by passing the appropriate flags, e.g.: $ c++ -o my_tb my_tb.cpp -I/opt/systemc-2.3.1/include -L/opt/systemc-2.3.1/lib-linux -lsystemc Due to this, you also usually include the SystemC header using #include "systemc" to indicate that it is not a standard system header. I suggest that you first test your SystemC installation by compiling, linking, and running a pure SystemC example (e.g., the single-file simple_perf example, which is distributed as part of the SystemC PoC implementation in the directory examples/sysc/simple_perf/). From your questions, it seems that you are not particularly familiar with C++ and the associated toolchains. I would recommend that you first learn about them before focusing on SystemC and then Nigram.
  9. Either you as the library author or the user of that library will need to provide at least an empty implementation of sc_main() to satisfy the linker. There is no way around it. I would like to also suggest that you update your SystemC installation to the latest version 2.3.3.
  10. value_changed_event() returns a constant reference to an sc_core::sc_event. A SystemC method or thread can be made sensitive to that event to get activated each time the corresponding sc_event gets notified. Easiest would be to connect your sc_signals to matching sc_in port of a dedicated module, which sets up the method or thread responsible for counting your bit changes. I recommend that you read a good introduction to the basic concepts of SystemC, e.g., David C. Black et al. "SystemC from the Ground Up", 2nd ed. The SystemC elaboration and simulation semantics are also described in clause 4 of the freely available IEEE Std 1666-2011. If you are not yet much familiar with C++ itself, it might be a good idea to get first familiar with the fundamental concepts of C++ first.
  11. The implementation of the TLM proof-of-concept library depends on SystemC. Therefore, you will need to link your application, which makes use of TLM, to the SystemC library. You can check it yourself by looking into the corresponding TLM headers: They include headers that are part of the SystemC implementation. Furthermore, the TLM implementation is not anymore header-only. The compiled .cpp implementation files are directly linked into the SystemC library file.
  12. Thanks for reporting this bug! I forwarded it to the SystemC Language Working Group, so that it can be fixed for the next release of the SystemC proof-of-concept library.
  13. Glad I could help! You have grasped the idea correctly.
  14. To achieve activation of your TDF controller only once per 5 activations of the valve and water tank modules, you will need to assign in addition to the time step also consistent rates to the TDF ports. E.g., you could assign to the TDF controller outputs command and threshold a rate of 5. Then, the connected valve and water tank modules will be activated 5 times per activation of the controller. As then the water tank will also output 5 times a water level sample to be read by the controller module, you will also need to assign a rate of 5 to the controller's input port. At this point, the TDF cluster is still not schedulable, as you have a feedback loop, which requires the insertion of a proper number of delay samples to achieve causality. To this end, you could, e.g., assign a delay of 5 to the controller input. For better understanding of the basic concepts of TDF modeling, I strongly suggest that you read at least the section 2.1 "Modeling fundamentals" of the SystemC AMS User's Guide available from the Accellera website.
  15. @Martin Barnasconi is of course right about that there is no SCA_ELN_MODULE macro defined in the SystemC AMS standard, as it is currently not possible to define own primitive ELN modules. Personally, I prefer to avoid the use of preprocessor macros in C++ as much as possible -- especially when a fully equivalent concise proper C++ syntax exist. In the context of SystemC (AMS) the macros SC_MODULE, SCA_TDF_MODULE, SC_CTOR, and SCA_CTOR obfuscate in my humple opinion more the code than they help to render SystemC models more readable. Your class LifELN is very probably a class derived from sc_core::sc_module (SC_MODULE) and which contains the netlist of your ELN model (i.e., a circuit of ELN primitives). The time step needs to be set always on at least one instance of a primitive SystemC AMS module, which is part of a cluster of connected SystemC AMS primitive modules. Therefore, your second approach: is the correct one.
  16. I have forwarded your issue to @karsten from COSEDA Technologies, as he is the principal author of the SystemC AMS PoC implementation.
  17. Thanks for reporting these compilation issues! These will need to get addressed by the COSEDA Technologies GmbH with a new SystemC AMS release. In the meantime, you can fix the compilation issue by replacing: pobj->sca_name() with this->name() The calls to memcpy() and memset() need to get prefixed with the std:: namespace prefix. The "register" storage class specifiers can be safely removed. If I see it correctly, they are only remaining in file scams/impl/analysis/ac/sca_ac_domain_entity.cpp.
  18. You seem to use the right approach of using an SC_MODULE to describe the structure of your circuit of ELN primitives. The macros SCA_ELN_MODULE and SCA_TDF_MODULE are exclusively used to define primitive modules in the respective MoCs, which describe the behaviour of the primitive, but not their inner structure. The statement from the SystemC AMS LRM regarding setting the time step refers to the set_timestep() member function, which is offered by all SystemC AMS primitive modules. To keep my models flexible, I tend to prefer to set the time step from the test bench or top level module by calling the set_timestep() member function of one of the accessible primitive AMS modules in that scope, i.e., usually a stimuli source. E.g., if you have instantiated a sca_eln:sca_vsource src1("src1", 2.0); you would call src1.set_timestep(10.0, sc_core::SC_US); to set the time step of the module src1 and the connected ELN cluster to 10 us. I hope that this answers your primary question. I definitely recommend you to read the SystemC AMS User's Guide to get a better insight into the fundamental concepts of SystemC AMS. It is an unfortunate situation that it is currently so hard to find as it is only provided as a bundled download together with the outdated Accellera SystemC AMS 1.0 standard. You can download it from the Accellera's SystemC standards page, where it is listed as "AMS 1.0" in the "Previous releases" section. The statements from this User's Guide are still relevant. It only lacks discussion of the advanced Dynamic TDF modelling features, which were added in SystemC AMS 2.0 and are also part of IEEE Std 1666.1-2016. Unfortunately, efforts to update the user's guide to the current SystemC AMS standard version got stalled due to lack of time of the involved people in the working group.
  19. Thanks for the clarification and feedback on the fix suggested by Philipp!
  20. Dear Guillaume, thanks for reporting this issue! I have forwarded your report to the Language Working Group for further analysis. From a first look, this is indeed a change in behaviour of the SystemC proof-of-concept implementation from version 2.3.1 to 2.3.2. However, it does not seem to touch the standard IEEE Std 1666-2011, as the latter does not mention member function `get_protocol_types()`. Regards, Torsten
  21. As you can see from the DDS block diagram, which you posted, the structure of DDS block is quite simple. I therefore would model it as a single TDF module containing the accumulator register as a state variable. As input, you will have your frequency control and phase offset control signals. The frequency control signal basically is the value, which you continuously add to the value in your accumulator register to generate a periodic sawtooth signal (due to the overflow of the accumulator). The phase offset control signal gets added to the accumulator register to enable shifting the phase of the sawtooth signal. This sawtooth signal is interpreted as the angle operand of a sine function. The period of the sawtooth signal represents a full revolution on the phase circle, i.e., the 2^L possible sawtooth signal values are evenly mapped to phase angles in the range of 0 rad to 2 pi rad (0° to 360°). To avoid repeated calculations of the sine function, the sine amplitudes for all possible angles are pre-calculated and stored in a look-up table (LUT). The current value of the sawtooth signal is then used as the index into that look-up table to find the corresponding output amplitude. To implement this in a generic DDS TDF module, I would choose M, L, and K (bit widths) as generic parameters, which can be passed upon DDS module instantiation to the DDS module's constructor. From M and L, you can calculate the value for the modulo operation, which models in software your overflowing of a M-bits-wide and L-bits-wide addition operation. The difference of M and L gives you the shift distance needed to implement your accumulator output quantisation. The sine LUT needs to have 2^L entries. The sine function should be scaled by 2^(k-1)-1 to use the full range of a k bit wide signed output. All these preparatory calculations, you can do in your DDS module's constructor. The processing function then only needs to only implement the two additions and the amplitude look-up based on the current values of the frequency and phase control inputs and the current value stored in the accumulator register. If you plan to use this kind of module in a model of communication system, you might consider having a look to the Vienna SystemC AMS Building Block Library, which is available for download from systems-ams.org. The latter web site contains also other useful SystemC AMS resources.
  22. Well, you will have to write a test bench, which provides your RC filter with some stimuli for transient simulation or sets up an AC analysis. However, I recommend you to have first a closer look to the fundamental concepts and ideas of SystemC AMS. A good introduction to SystemC AMS is provided by the SystemC AMS extensions User's Guide, which is part of the SystemC AMS extensions 1.0 release. Even though, this discusses only the features available sind SystemC AMS 1.0, it is a good start as SystemC AMS 2.0 and IEEE Std 1666.1 added mainly advanced features related to Dynamic TDF and bug fixes. Also, the SystemC AMS community pages provide some good links to introductory resources to get started with SystemC AMS.
  23. Thanks for providing this feedback on the SystemC PoC implementation! It would help if you could share some more details about the exact error messages as well as a minimal self-contained example exposing the problem you are observing. Then, we may discuss the issue more seriously.
  24. Thanks for reporting this Aarm64-specific issue! I have forwarded it to the Language Working Group's bug tracker so that we can have a look. Support for Aarm64 in SystemC is relatively new. To help localise the source of the problem, could you try whether it helps to configure SystemC to use Pthreads instead of QuickThreads in addition to `--enable-debug --disable-optimize`?
×
×
  • Create New...