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The token stream from step 1 is translated into typed tokens like DelimiterToken :EndToken ; or subtypes of KeywordToken. These tokens are then grouped into blocks. The following screenshot shows the resulting stream of blocks:. This is shown in the next screenshot:.
One of many post processing steps could be to remove whitespaces, indentation and comment blocks. So a filter can be applied to remove these block types.
Additionally, multiparted blocks e. This screenshot shows the filtered results:. This is the result stream:. And this is the filtered and fused result stream:.
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Programming FPGAs With Python
Change your preferences any time. Stack Overflow for Teams is a private, secure spot for you and your coworkers to find and share information. Is there a reference, paper, or tutorial that shows how to do this?
I've checked the Xilinx, Altera, and Modelsim websites but could not find anything. Python is an efficient language for writing reference models in or to process and verify output files of your testbench. One key feature of Python that makes it so suitable is the automatic usage of big integers. Also when verifying arithmetic functionality, e. Python's Decimal package is a convenient tool to build high-precision references.
A straightforward practical way to interface Python is via input and output files. You can read and write files in your VHDL testbench as it is running in your simulator. Usually each line in the file represents a transaction. Depending on your needs, you can either have the VHDL testbench compare your design outputs to a reference, or read the output file read back into a Python program.
If using files takes too long, at least in Linux it's easy to set up a pipe with mkfifo that you can use as if it were a file, and you can then have your Python program and simulator read from and write to in sync. With the method I described, you'll have to find a way to separate whatever that module is doing into a stream of data or raw transactions. Still it gets complicated really fast. But, you are better off performing verification in a native environment using a language that was developed to perform functional verification.
Using Systemverilog and the Modelsim superset packaged as "Questa Prime" if you have access to it is much better. Unfortunately, VHDL is not a verification language, even with the additions they have made to be more like SV, it is, still, better categorized as a modeling language.
Learn more. Asked 4 years, 1 month ago. Active 1 year, 3 months ago. Viewed 5k times. Questions: How is this done? Is this done by writing a test bench in Python and then compiling this Python file or linking into Modelsim?
Is so, how is the timing diagram generated? Rao DigitalOne DigitalOne 49 1 1 silver badge 3 3 bronze badges. See also: cocotb. Look at Chris Higgs answer to Can you interface a Modelsim testbench with an external stimuliwhere in the link to Tutorial: Ping.
One example of a Python test suite that can drive a Modelsim process. Active Oldest Votes. Why Python is good for this Python is an efficient language for writing reference models in or to process and verify output files of your testbench.From this, a hardware description can be uploaded to an FPGA. Hats off to [hardsoftlucid] for sending this in. Our wonderful we mean that, really noticed a few mistakes when this was first posted. Those mistakes have been corrected.
This seems pretty cool, but I recently got the hang of Verilog and found it easier to learn than Python. This appears to compile your code, and includes an embedded CPU to run it. The hardware equivalent of runtime I guess? That seems pretty useful. I have only used CatapultC, Handel-C and Impulse C and all of those tools convert code direct to gates and flip-flops. Catapult analyzes code for loops and automatically unrolls them into pipelines.
Handel-C on the other hand blindly converts variables to registers and program flow into a state machine without attempting to reuse any logic. If you want pipelines, you have to parallelize the code explicitly.
Depends on how you define usefull. If your purpose is to broaden and facilitate the use of FPGAs in the hacking community, than any addition to the already availlables programing languages is usefull.
MyHDL is a hardware description language comparable to VHDL or Verilog which uses a python like syntax note: hardware description languages are very different to conventional programming languages, they are used for describing the physical arrangement of logic gates on silicon, programming languages are a series of instructions fed into a CPU which already exists on silicon.
It is a CPU architecture which is optimized to run python byte-code.
It seems like a really awesome idea given that most CPU architectures nowadays are targeted towards running compiled C.
Really interested in what comes of the project. Especially in the sentence: The portion of the Python language supported by MyHDL is extremely minimal, with only ints being the only built-in data type supported. A couple of corrections: MyHDL is implemented as a Python package, and therefore it is pure Python, not just python-like. HDLs support concepts like structure, time, hardware-friendly datatypes and fine-grained concurrency, but really are not that different from general programming languages.
MyHDL shows this by implementing all these concepts within Python. Finally, HDLs are used to describe the functional behavior of hardware systems, not the physical arrangement of gates.
I think you may have confused two separate projects. This in itself is a really interesting idea as most CPU architectures are optimized for running compiled C code. Really interested in where this project ends up. For large sets of test data, VHDL will having you tearing your hair out. There are simple choices out there, if you want JUST to program, there are microcontrollers out there, raspberry pis, that give way less headache than FPGAs.
Sorry, but anyone who uses this to learn about FPGAs will be denying themselves a lot of enlightenment. Please try it before making any judgements. This is not a new project, several years old and was built for real projects at a company that does FPGA work.
This is not a toy or untested, it has been used in production.It cleanly integrates the general purpose Python programming language with the specialized VHDL hardware description language. You can use all the great features of Python to quickly create your testbench. Some advantages of using Python include:. Python can be used for more than just testbenches.
Concurrent Python processes can wait for signal transitions, wait for a specified period of time, read values of signals in the design, or update the values of signals with an optional delay. This capability is useful for quickly prototyping the behavior of an entity, or emulating complex behavior like a memory device or UART. PyVHDL features a unified execution environment.
There is no overhead wasted on passing data and maintaining synchronization between separate Python and VHDL environments. For example, using the Cython optimising compilerthe speed of the simulator event queue can be improved by more than a factor of seven.
The simulator is written in Python, a language familiar to many programmers. Python is much easier to read and modify compared to most languages. Also, the hurdle of setting up an obscure tool chain environment is not an issue. Features provided by zamiaCAD include:. PyVHDL 0. Not all VHDL syntax is supported. Un-supported VHDL syntax includes:. PyVHDL latest. Quickstart Write a Python testbench License.
The dark mode beta is finally here. Change your preferences any time. Stack Overflow for Teams is a private, secure spot for you and your coworkers to find and share information. I want to have many sensors hooked up to a device, and as the data comes in, calculations are done very quickly so it can be displayed on a video wall, so the FPGA would have as input dozens of sensors and several video controllers for the wall.
This is a library for code written in Scala. For this one I am curious if the code is written in Java and Scala would that affect what it generates. I would prefer simplifide, as I am stronger at Scala than Python, but it seems that myhdl may be a more robust platform, just from some basic looking around.
Examples of VHDL Conversions
The reason for the FPGA is that it can do multiple tasks at one time very well, so when the data comes in, depending on the needs of users, based on the experiment, it would be easy to change the code on the FPGA to be able to adapt to the needs.
So, for example, if you have 8 x 3 different weather sensors on each floor of an office building, so there are temperature, wind speed, barometric sensors 8 of each sensor one each floorand add sensors to test the deformation of the walls, then a real-time interface to read these in at the same time and keep updating the visual display may be helpful. This is a made up example, but it would explain why an FPGA would be useful, otherwise I would need many different DSPs and then feed that into a computer to do the visual display, whereas an FPGA can do is faster, since it is hardware, with lower power needs.
This is just one example. The visual environment of LabView is a reasonable fit for FPGA programming, and it takes care of many of the annoying details for you unless you must worry about them as part of the algorithm, e. Yes there is a python style HDL available and its free.
This will generate VHDL or verilog. It can also simulate the code and output. VDI and you can look that in gtkwave. All these are open source. Build and simulate using these tools. To flash into the FPGA you need either xilinx or Altera tool chains to generate the bitstreams and flash them. All the best!Is there the tool that can turn python into HDL? Not in general terms. View solution in original post. I agree, I tried it out too and it did not work out so well. There were plenty of issues just during the first 5 mins of usage alone that I gave up right then and there.
As the author of LiteEth mentioned above, there is no magic with these tools. Even i'm not a MyHDL user, i'm sure the same comments applies to it. Don't expect these tools to be magic, try them for at least a couple of days, understand what they are doing and how it can pay back for your productivity :. Thanks for the reply! That seems like an excellent strategy, because Vivado's UI performance and presumably the underlying TCL is extremely poor.
I'm sure everyone here has wandered off to get a coffee or equivalent while waiting for Vivado to finish connecting up a block diagram. Being able to speed that up - and save a significant amount of space - is very valuable. Sign In Help. Turn on suggestions. Auto-suggest helps you quickly narrow down your search results by suggesting possible matches as you type. Showing results for. Search instead for. Did you mean:.
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Accepted Solutions. Re: python to HDL. Codes are on GitHub. But I am wary about such things. All PMs will be ignored This chapter describes the concepts of conversion. Concrete examples can be found in the companion chapter Conversion examples. To be convertible, the hardware description should satisfy certain restrictions, defined as the convertible subset.
This is described in detail in The convertible subset. The conversion does not start from source files, but from an instantiated design that has been elaborated by the Python interpreter. It then selectively compiles pieces of source code for additional analysis and for conversion.
In MyHDL, working with negative numbers is trivial: one just uses an intbv object with an appropriate constraint on its values. In contrast, both Verilog and VHDL make a difference between an unsigned and a signed representation. To work with negative values, the user has to declare a signed variable explicitly.
But when signed and unsigned operands are mixed in an expression, things may become tricky. In Verilog, when signed and unsigned operands are mixed, all operands are interpreted as unsigned. Obviously, this leads to unexpected results. The designer will have to add sign extensions and type casts to solve this.
In VHDL, mixing signed and unsigned will generally not work. The designer will have to match the operands manually by adding resizings and type casts. It uses signed or unsigned types based on the value constraints of the intbv objects, and automatically performs the required sign extensions, resizings, and type casts. Unsurprisingly, not all MyHDL code can be converted. Although the restrictions are significant, the convertible subset is much broader than the RTL synthesis subset which is an industry standard.
However, it is also possible to write convertible code for non-synthesizable models or test benches. The converter attempts to issue clear error messages when it encounters a construct that cannot be converted. Recall that any restrictions only apply to the design after elaboration. In practice, this means that they apply only to the code of the generators, that are the leaf functional blocks in a MyHDL design. A natural restriction on convertible code is that it should be written in MyHDL style: cooperating generators, communicating through signals, and with sensitivity specify resume conditions.
The most important restriction regards object types. Only a limited amount of types can be converted. All other supported types need to have a defined bit width. This can be done by specifying minimum and maximum values, e. The Verilog converter supports intbv objects that can take negative values. Alternatively, a slice can be taken from an intbv object as follows:. In addition to the scalar types described above, the converter also supports a number of tuple and list based types. The mapping from MyHDL types is summarized in the following table.
The table as presented applies to MyHDL variables. The converter also supports MyHDL signals that use boolintbv or enum objects as their underlying type. The converter supports MyHDL list of signals provided the underlying signal type is either bool or intbv.