Reusable Automated Agent For Universal Verification Methodology System Testbench

Pre-silicon verification process is an important cog in an application specific integrated chip design cycle. It is considered one of the biggest bottle-neck in modern day design projects. Thus, verification efficiency and productivity has gained a lot of attention lately and will be the driving factor of this research. The purpose of this research is to build a verification solution that actively promotes reusability and interoperability of verification components and improve the automation within the verification solution. These are identified as important concepts to improve verification efficiency and productivity. A state of the art UVM (Universal Verification Methodology) verification solution centered on these concepts is built for the sideband module of a hard memory controller. First, the verification requirements of the sideband module are investigated. Next, existing testbench solutions were evaluated for its reuse capabilities. This is followed by proposing and implementing a testbench architecture that highly reuses existing verification components and be reused friendly itself. Next, the architecture is improved to allow higher level of automation within the testbench. The implemented verification solution is then measured and analysed for its reusability and automation. The result obtained shows the implemented verification solution achieves a reusability of 21.70% in a system level testbench and 49.67% in the standalone sideband verification environment. In addition, the autonomous agent approach implemented in the architecture reduces the test writer's burden by at least 60% and up to 78%

Analyzing UVM reuse

Abstract. This thesis investigates Universal Verification Methodology’s (UVM) reuse possibilities. Initally, the object-oriented features of the UVM’s programming language SystemVerilog (SV), are introduced. Those features are one enabling factor in UVM reuse. The work also provides a brief overview to the development history of UVM and presents its properties. The structure of a conventional UVM testbench is also demonstrated. Finally, the features that make the UVM testbench more reusable are briefly introduced. In the practical part of the study, a UVM testbench is made for Nordic Semiconductor’s Introproject. The testbench was created with extensive comments so that beginners would get the most out of it. The methods that make the testbench reusable are also applied to the testbench. At the end of the practical part, the reuse possibilities of the testbench were tested by changing the Design Under Test (DUT). Modifications were made to the testbench in order to match the new features of the DUT.UVM uudelleenkäytön analysointi. Tiivistelmä. Tämä diplomityö tutkii Universaalin varmennusmenetelmän (UVM) uudelleenkäyttömahdollisuuksia. Aluksi UVM:n ohjelmointikielen, SystemVerilogin olio-ohjelmointipohjaisia ominaisuuksia käydään läpi. Nämä ominaisuudet ovat yksi mahdollistava tekijä UVM uudelleenkäytössä. Työssä tehdään lisäksi lyhyt katsaus UVM:n kehityshistoriaan ja esitellään myös sen ominaisuudet sekä tavanomaisen UVM-testipenkin rakenne. Lopuksi esitellään lyhyesti ominaisuuksia, jolla saa tehtyä UVM testipenkistä paremmin uudelleenkäytettävän. Työn käytännön osuudessa tehdään UVM-testipenkki Nordic Semiconductorin Introprojektiin. Testipenkki tehtiin laajasti kommentoimalla, jotta aloitteleva testipenkin tekijä saa siitä mahdollisimman paljon irti. Testipenkin tekemisessä käytettiin myös menetelmiä, joita esiteltiin aiemmassa teoriakappaleessa. Käytännön osuuden lopuksi testattiin testipenkin uudelleenkäyttöä muuttamalla testissä olevaa komponenttia. Testipenkkiin tehtiin muutokset, jolla se saatiin taas vastaamaan komponentin tarpeita

Integration and verification of parameterized register interfaces

Abstract. This thesis takes an in-depth look on parameterized register models, their generation and use. The aim is to discover improvements to the current method of generating parameterized register models. The thesis is divided into two halves: a practical section that consists of a study on the generation of parameterized register models, and a theory section that supports the topics gone over in the practical section. The practical section studied the generation flow and tools currently used at Nordic Semiconductor. The flow was analyzed to discover changes that would enable the generation of more flexible parameterized register models. The suggested changes were then used to generate a dynamic register model for a highly configurable intellectual property (IP) core. The register model was validated using a register test sequence and functional tests. Finally, the functionality of the generated register model was compared to a manually implemented model. In the end, the test sequences and functional tests passed without errors. The generated register model could be configured directly from the testbench without editing the model manually. This also meant that the applied configurations would not be lost even if the register model were to be regenerated. The resulting register model was significantly more flexible than the previous generated models.Parametrisoitujen rekisterirajapintojen integrointi ja verifiointi. Tiivistelmä. Tässä opinnäytetyössä tutustutaan parametrisoituihin rekisterimalleihin, niiden generointiin, ja niiden käyttöön. Tavoitteena on löytää parannuksia nykyiseen parametrisoitujen rekisterimallien generointitapaan. Opinnäytetyö on jaettu kahteen puoliskoon: käytännön osuuteen, joka koostuu parametrisoitujen rekisterimallien tutkimuksesta, ja teoreettisesta osuudesta, joka tukee käytännön osuudessa käsiteltyjä aiheita. Käytännön osuus tutki Nordic Semiconductorilla tällä hetkellä rekisterimallin generointiin käytettyjä prosesseja ja työkaluja. Niitä analysoimalla pyrittiin löytämään muutoksia, joiden avulla voisi generoida joustavampia parametrisoituja rekisterimalleja. Kyseisten muutosten avulla generoitiin sitten dynaaminen rekisterimalli IP lohkolle, joka sisältää paljon konfiguroitavia parametrejä. Generoitu malli varmennettiin rekisterien testisekvenssillä ja toiminnallisilla testeillä. Lopuksi rekisterimallin toiminnallisuutta verrattiin käsin kirjoitetun rekisterimallin toiminnallisuuteen. Testisekvenssi ja toiminnalliset testit läpäistiin simuloinnissa lopulta ilman virheitä. Generoitu rekisterimalli oli konfiguroitavissa suoraan testipenkistä, eikä sitä tarvinnut muokata manuaalisesti. Tämä tarkoitti myös sitä, että testipenkissä asetettuja konfiguraatioita ei menetetä, jos rekisterimalli generoidaan uudelleen. Lopullinen rekisterimalli oli merkittävästi joustavampi kuin aikaisemmat generoidut mallit

Automated UVM testbench generation

Abstract. This thesis studies the possibilities to automate UVM testbench creation in the telecommunications industry. First, the ideas behind UVM are looked at and automatable parts of the testbench coding process are studied. Facilitating the reuse of code is also examined. Development of an automation script with python for Nokia is covered in the work, and the possibilities for future improvements are discussedAutomatisoitu UVM testipenkin generointi. Tiivistelmä. Tämä kandidaatintyö tutkii mahdollisuuksia automatisoida UVM testipenkin kehitystä tietoliikennetekniikan saralla. Aluksi käydään läpi UVM:n taustaideat ja pohditaan automatisoitavia osia koodausprosessissa. Koodin uudelleenkäytettävyyttä tutkitaan myös tarkasti. Työssä käydään läpi automaatioskriptin kehitys Nokialle pythonilla ja mietitään mahdollisia suuntia jatkokehitykselle

An Application of the Universal Verification Methodology

The Universal Verification Methodology (UVM) package is an open-source SystemVerilog library, which is used to set up a class-based hierarchical testbench. UVM testbenches improve the reusability of Verilog testbenches. Direct Memory Access (DMA) plays an important role in modern computer architecture. When using DMA to transfer data between a host machine and field-programmable gate array (FPGA) accelerator, a modularized DMA core on the FPGA frees the host side Central Processing Unit(CPU) during the transfer, helps to save FPGA resources, and enhances performance. Verifying the functionality of a DMA core is essential before mapping it to the FPGA. In this thesis, we tested an open source DMA core with UVM (Universal Verification Methodology). Bus agents and interface modules are designed for input and output signals of the DMA Design Under Test (DUT). We constructed a Register Level Abstraction (RLA) model to allow both front-door access and back-door access to the register files in the DUT. We designed the sequences, scoreboards, and tests with features to allow reuse. The overall testbench structure is defined by a base-type test. Different tests then extend the base-type test and use type overriding with the UVM configuration database to use different scoreboards and sequences accordingly. With scoreboard and coverage groups, the testbench monitors the correctness of the behavior of the DMA DUT, as well as the functional coverage of all tests. We performed the simulations with the Questa simulator. Several bugs in the open-source DMA core were found and corrected

VeriSFQ - A Semi-formal Verification Framework and Benchmark for Single Flux Quantum Technology

In this paper, we propose a semi-formal verification framework for single-flux quantum (SFQ) circuits called VeriSFQ, using the Universal Verification Methodology (UVM) standard. The considered SFQ technology is superconducting digital electronic devices that operate at cryogenic temperatures with active circuit elements called the Josephson junction, which operate at high switching speeds and low switching energy - allowing SFQ circuits to operate at frequencies over 300 gigahertz. Due to key differences between SFQ and CMOS logic, verification techniques for the former are not as advanced as the latter. Thus, it is crucial to develop efficient verification techniques as the complexity of SFQ circuits scales. The VeriSFQ framework focuses on verifying the key circuit and gate-level properties of SFQ logic: fanout, gate-level pipeline, path balancing, and input-to-output latency. The combinational circuits considered in analyzing the performance of VeriSFQ are: Kogge-Stone adders (KSA), array multipliers, integer dividers, and select ISCAS'85 combinational benchmark circuits. Methods of introducing bugs into SFQ circuit designs for verification detection were experimented with - including stuck-at faults, fanout errors, unbalanced paths, and functional bugs like incorrect logic gates. In addition, we propose an SFQ verification benchmark consisting of combinational SFQ circuits that exemplify SFQ logic properties and present the performance of the VeriSFQ framework on these benchmark circuits. The portability and reusability of the UVM standard allows the VeriSFQ framework to serve as a foundation for future SFQ semi-formal verification techniques.Comment: 7 pages, 6 figures, 4 tables; submitted, accepted, and presented at ISQED 2019 (20th International Symposium on Quality Electronic Design) on March 7th, 2019 in Santa Clara, CA, US

Reusable Verification Environment for a RISC-V Vector Accelerator

This paper presents a reusable verification environment developed for the verification of an academic RISC-V based vector accelerator that operates with long vectors. In order to be used across diverse projects, this infrastructure intends to be independent of the interface used for connecting the accelerator to the scalar processor core. We built a verification infrastructure consisting of a Universal Verification Environment (UVM) which is capable of validating the design performing co-simulation of the vector instructions. Moreover, we provided a set of tests and an automated test generation, simulation and error reporting infrastructure. This paper shares our experience on verifying a complex accelerator used in two distinct projects, with different interfaces.This research has received funding from the European High Performance Computing Joint Undertaking (JU) under Framework Partnership Agreement No 800928 (European Processor Initiative) and Specific Grant Agreement No 101036168 (EPI SGA2) and No 956702 (eProcessor) . The JU receives support from the European Union’s Horizon 2020 research and innovation programme and from Croatia, France, Germany, Greece, Italy, Netherlands, Portugal, Spain, Sweden, and Switzerland. The EPI-SGA2 project, PCI2022-132935_N1618737 is also co-funded by MCIN/AEI /10.13039/501100011033 and by the UE NextGenerationEU/PRTRPeer ReviewedPostprint (author's final draft