This is a warning being produced by yosys during synthesis which leads to an error in placement down the line when using OpenROAD

@User This is actually not a problem from yosys. This is due to that you are the technology mapped netlist from OpenFPGA, which is not synthesizable. The use of technology mapped netlist is to drive the place & route of OpenROAD directly. Or you can try our synthesizable netlists at https://github.com/lnis-uofu/OpenFPGA/tree/master/openfpga_flow/tasks/fpga_verilog/verilog_netlist_formats/synthesizable_verilog/config

Actually there was a problem with the mapped netlist, as some cells weren't properly mapped to the library so I was setting things don't touch and trying to re-synthesize it but I'll have a look at these, Thanks

Hi all, I am trying to generate FPGA fabric using standard cells by following tutorial given in https://openfpga.readthedocs.io/en/master/tutorials/arch_modeling/open_cell_libraries_tutorial/ But iverilog doesn't look for verilog files in the include directory specified in iverilog_output.txt file i.e. iverilog -o compiled_and2 ./SRC/and2_include_netlists.v -s and2_top_formal_verification_random_tb -I ${OPENFPGA_PATH }/skywater-pdk/libraries/sky130_fd_sc_ls/latest/cells/or2 And generates error as shown in the screenshot attached As a work around I added absolute path in the .v file of the cell included, which worked. Does anyone know why it isn't it searching in included directory for the file defined by -I flag in the iverliog_output.txt file. But even after using the work around, it says simulation successful but for some reason the logs and vcd for the test isn't being generated. It works fine before replacing the cell with the sky130 one, in the xml. Any help would be much appreciated.

Hi! Did you use vcs for your verification? Are you getting compile errors with

libs.ref/sky130_fd_sc_hd/verilog/primitives.v

@User I have not used VCS for Skywater PDK. But we do have seen some errors when using Modelsim. https://github.com/google/skywater-pdk/issues/198#issuecomment-832505962 See details in the Github issue and hope it can help you find a solution

Thanks @User Do you have a .v that compiles?

@User Yes. We changed the default_net_type to wire and hacked some verilog netlists. This works. Also we have try the openPDK, which process the Verilog netlists in a similar principle as our hacking. It also works.

@User yes, it seems to compile now. Just worried I am doing something wrong. Thanks!

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Exclusive VSD-HDP for Front-end, FPGA, EDA and RISC-V As you know, there are a lot of requests on VSD based Front-end, FPGAs and RISC-V hardware design programs, so here is the list of projects under the exclusive guidance and mentorship of Steve Hoover, Founder of RedWood EDA. Now the word exclusive plays a bigger role here, as the projects listed below are the future of our VLSI industry and getting hold of these projects means you have secured a position in the present and future of the semiconductor industry. Important Note - Interested participants can reply back to this message asking for a detailed description and we will send it across Link for registration - https://www.vlsisystemdesign.com/hdp/ Program start/end date - 2nd January to 13th March, 2022

Cloud FPGA workshop in VSD style First let me tell you why we are doing this? Because of you, our students, our global participants, our corporate customers. About a year back, we were introduced to existing FPGA training programs in colleges and institutes. VSD analyzed the content and it looked quite common across all institutes VSD had to differentiate and restructure the entire content, and it took close to 8-months of planning, recording and building the entire cloud platform for global students. If you closely look into FPGA programming methodology for any board, the fundamentals are same. Its the FPGA fabric which plays a crucial role while deciding on number of LUTs, performance, area, power. So this short 5-day workshop purpose to create an awareness about, FPGA fabrics and its relevance in FPGA programming, thereby opening new opportunities, especially for freshers, looking for core FPGA jobs and projects Really Thankful to Prof. Nanditha Rao and Dr. Xifan TANG from Open-Source FPGA Foundation for being the torch bearer of this initiative. Also thankful to Hugo A. Andrade and Parimal Patel from Xilinx who have been very helpful from day 1 when we planned this workshop. All of them are examples of courageous and dedicated leaders who look differently at future of Semiconductor industry I am sure, this project, this workshop and this team is just the beginning of a bigger mission to make each country build their own FPGA fabrics and hence their own FPGA boards Here's the registration link with more details. Stay tuned for more posts about this workshop https://www.vlsisystemdesign.com/fpga/

FPGA banner.jpg

Why settle for less, when you can get more in 5-days? Now me and my team did a quick research. We haven't seen any FPGA coursework which gives lab based overall view about FPGA design, architecture and fabric The distinct fundamental differences between FPGA IP designer and FPGA application designer (which are 2 job roles by itself) needs to come out with labs that will help community to choose the right career path Looking forward to interact with FPGA beginners and experts through this workshop, and plan good research projects in areas of FPGA design, Fabric and architecture Here's the registration link https://www.vlsisystemdesign.com/fpga/

Upcoming FPGA workshop content - Its an elegant blend of Xilinx Vivado, RISC-V, OpenFPGA and SOFA Sky130 FPGA architecture. Details are in below link: https://www.vlsisystemdesign.com/fpga/ This workshop opens up new opportunities for students around the globe who learn how to use, design and build FPGAs from scratch, and may be, the next democratization of hardware design Amazing job by entire team Nanditha Rao, Xifan TANG, Open-Source FPGA Foundation All the best and see you in workshop

And the countdown begins - Registration for FPGA closes in 4-days Registration link - https://www.vlsisystemdesign.com/fpga/ Workshop Day-wise content is here Day1: 1. Introduction to FPGA 2. Counter example using Vivado 3. Counter Verilog explanation and implementation using Vivado 4. Vivado timing, power, and area measurement for counter 5. Introduction to VIO Day2: 1. Introduction to OpenFPGA and VTR (verilog-to-routing) 2. Introduction to VPR (versatile-place-and-route) using basic Earch fabric 3. Counter example using VPR/VTR openfpga flow Day3: 1. Introduction to basic RISC-V core – rvmyth 2. Rvmyth – Vivado RTL to synthesis flow 3. Rvmyth – Vivado Synthesis to bitstream Day4: 1. Introduction to opensource SOFA FPGA fabric 2. Steps to run counter example on SOFA 3. Characterize counter example in terms of area and timing 4. Post-implementation netlist and simulation using SOFA Day5: 1. Steps to run RISC-V Core - on SOFA 2. Characterize RVmyth in terms of performance and area 3. Steps to generate rvmyth post-implementation netlist 4. Confirm RVmyth on SOFA behavioral simulation using Vivado

[Last 2 days] FPGA power, performance, area analysis There is a reason why our seniors have been asking us to focus on fundamentals rather than tools. Fundamentals of an FPGA power, performance and area analysis is very similar to that of an SoC. Techniques to measure them are tool dependent. VSD team has an advantage of having SoC and Embedded background, which helped to compare both flows in terms of time-to-market and PPA There are many such interesting details (including the above one) being covered as a part of an upcoming FPGA workshop. This is one of its kind, state-of-the-art workshop, where we are not only just building applications using Xilinx Basys boards, but we are entering into FPGA chips and exploring what exactly is happening there, from SoC point of view Registration link (Last 2 days) https://www.vlsisystemdesign.com/fpga/ Your FPGA journey doesn't end there. We are planning some cool (paid) hardware design programs in and around FPGAs with our OpenFPGA partners. Planning is underway. Stay tuned. All the best and happy learning

If you are an ASIC or Physical Design engineer, you will be so amazed to know about the similarities between FPGA and ASIC PNR flow. Fundamentals remain so same, just different modes of configuring 2 different systems I am very sure, after this workshop, all of you Physical Designers will question - why haven't we explored FPGAs before? If you have an RTL, and want to quickly check its performance on real hardware, FPGA is the way to go about Here's the registration link [Valid for last 15hrs] https://www.vlsisystemdesign.com/fpga/ All the best and I will see you in workshop

Hello everybody, could someone tell me what is the example task to run the Formal-oriented Testbench?

Hi! I could need an FPGA that primarily consists of XOR and Majority gates, has anyone done something like that?

And perhaps some SRAM too

A lookup table can be configured as a XOR or majority gate. Do you need it to be a hardwired element?

Hmm, I guess for MAJ-3 and MAJ-5 a lookup table is a good idea, for MAJ-7 and MAJ-9 I guess hardwired elements might be better?

Hai all, Herewith I have attached the screenshots of LUT4AB tile running flow and .JSON which is used for eFPGA. Kindly suggest your ideas with me to rectify setup violation. Advance thanks.

Hello all, I am trying to generate gds for an eFPGA using Open Lane. I got gds but the flow is failing due to LVS error. Herewith, I have attached the log file for the reference. Kindly share your ideas with me to rectify the LVS violation. Advance thanks.

Hai all, Is there any public template available (other than a Caravel project template) in eFabless? If yes, kindly share with me the details. Advance thanks.

Dear all, Good noon, I am facing LVS issues with BRAM using OpenLane. Herewith, I have attached the tiles for your kind reference. Kindly share with me your ideas to clear the same.

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