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Skip Initialization for DDR VIP Models

Posted by VIP Experts on September 3rd, 2015

In the blog Seamless Fast Initialization for DDR VIP Models, we discussed how important it is for Memory VIP simulations to have the option of going through the process of Reset and Initialization fast, and get to the IDLE state and start reading and writing to memory location. We presented one way to achieve this by scaling down the timings required while going thru all the JEDEC standard steps required for Reset and Initialization.

In this blog, we will discuss how Synopsys Memory VIP allows skipping initialization altogether while maintaining the proper behavior of the model.

You can learn more about Synopsys Memory VIP here.

Using the Synopsys Memory VIP’s Skip Initialization feature ensures that the model will be in an IDLE state, bypassing the requirements for the reset process. In that state, the VIP is ready to accept commands like REF, MRS, and ACT. The allowed commands are illustrated below in Figure 1 – The DDR3 SDRAM JEDEC standard JESD79-3F State Diagram, and Figure 2 – The DDR4 SDRAM JEDEC Standard JESD79-4 State Diagram.

DDR3-JEDEC

Figure 1 – The DDR3 SDRAM JEDEC standard JESD79-3F State Diagram

DDR4-JEDEC

Figure 2 – The DDR4 SDRAM JEDEC Standard JESD79-4 State Diagram

The Skip Initialization feature is applicable for DDR3, DDR4, and LPDDR. It should be noted that a reset after backdoor settings using skip init will wipe out all the settings and set back to default.

For Discrete devices, we can use the following to set the VIP to skip initialization mode:

// dram_cfg is handle of class svt_ddr_confitugation
dram_cfg.skip_init = 1

For DIMM devices, we can use the following steps to set the VIP to skip the initialization sequence on a DIMM Model:

// dimm_cfg is handle of svt_ddr_dimm_configuration and
// configuring the skip_init setting for individual DRAM
// configurations with DIMM structure
foreach(dimm_cfg.data_lane_cfg[i]) begin
   foreach(dimm_cfg.data_lane_cfg[i].rank_cfg[j]) begin
      dimm_cfg.data_lane_cfg[i].rank_cfg[j].skip_init = 1;
   end
end
// Skip initialization setting for RCD component within an
// RDIMM and LRDIMM
dimm_cfg.ca_buffer_cfg.skip_init = 1;

Skip initialization setting for Discrete as well as DIMM models should be done in the build phase before passing the configuration object through the config_db mechanism.

Also, these settings can be done after build phase but user will have to call reconfigure() method to update the settings in the model. This has to be done prior to any command on the interface.

The following is the syntax for reconfigure() method call:

// For Discrete Device Model
env.mem_agent.reconfigure(dram_cfg);

// For DIMM Model
env.dimm_env.reconfigure(dimm_cfg);

In subsequent blogs, we will discuss how Mode Registers can be set using Frontdoor and Backdoor accesses. So do come back and check it out.

Authored by Nasib Naser

You can learn more about Synopsys Memory VIP here.

Posted in DDR, LPDDR, Memory, Mobile SoC, Processor Subsystems | No Comments »

MIPI Soundwire Test Suite

Posted by VIP Experts on August 27th, 2015

Here, we describe how easy it is to integrate and validate a SoundWire design using Synopsys SoundWire VIP Test Suite.

Often Verification IP and design integration require in-depth understanding of the protocol and methodology. This requires significant investment of time in building the expertise in-house. To accelerate the process, Synopsys’ Soundwire VIP solution is written in 100% native SystemVerilog to enable ease-of-use, ease-of integration and high performance. In addition, we provide test suites that are complete, self-contained and design-proven testbenches, written in SystemVerilog UVM and targeted at protocol compliance testing. These are provided as source code enabling users to easily customize or extend the environments to include unique application-specific tests or corner-case scenarios. Using Synopsys VIPs and Test Suites, our users have reduced verification time from months to a few hours in some cases.

Soundwire Test Suite Architecture

Verification IP and RTL Design integration is one of the areas where a good test suite architecture helps the most. It is easy to plug-in the design with verification IP if test suite environment is designed keeping various design configurations in mind. The figure below illustrates our Test Suite architecture. Soundwire-TS-Architecture

The intention of this architecture is to make the environment design independent so that it can work with any design with little or no effort. In this figure, dark and light purple color blocks are provided with Test Suite, user intervention is only required in light purple color boxes to customize the environment to specific DUT. These changes are one time changes and all existing tests and sequences should run as it is after the changes. This significantly reduces verification time of any design, while giving the user a lot of flexibility to write their own test and sequences for design specific test scenarios.

In this white paper, you can learn how a customer was able to integrate the SoundWire Test Suite to verify SoundWire Slave IP of a third party vendor and begin test runs within 8 hours. To learn more about the basics of digital audio transmission and MIPI Soundwire, you can download this whitepaper

Posted in Audio, Interface Subsystems, MIPI, Mobile SoC, Soundwire | No Comments »

Seamless Fast Initialization for DDR VIP Models

Posted by VIP Experts on August 20th, 2015

DDR verification is one of the most critical and complex tasks in any SoC as it involves a controller sitting inside the DUT and an external DDR memory sitting outside the DUT on board. Here we will discuss fast initialization for DDR VIP models.

You can learn more about Synopsys Memory VIP here.

As per the JEDEC standard JESD79-4, Section 3.3.1, RESET_n needs to be maintained for a minimum of 200us. In simulation time, this value is a very long time. Furthermore, if the user’s testbench violates this timing, the Memory VIP will flag it as a UVM_ERROR and fail the simulation. Even though this violation is flagged as an error, it doesn’t affect the behavior of the VIP model.

DDR-init

There are a number of ways to get around this violation. In this blog, we will discuss one of these ways.

The Synopsys Memory VIP has an initialization feature called Fast Initialization, also known as, scaled down initialization. The intention of this feature is to allow control for overriding the initialization parameters to speed up the initialization process. The new values, whether they are set by default or customized by the user, enable faster initialization times without asserting any checker violations. Also, it doesn’t affect the initialization behavior of the model. This feature is only available for front door access – vs. backdoor access. We will discuss types of Memory VIP access in subsequent blog posts.

There are two ways to scale down the initialization parameters. One is set by using default values, and another by customization.

As per the standard, the following are the expected values:

min_cke_high_after_reset_deasserted_in_pu_and_res_init_time_ps = 500000000
min_reset_pulse_width_in_pu_ps = 200000000

Using the default approach, one may call the function “set_scaled_initialization_timings()” from the build_phase of the configuration object. That function call will scale down the timing parameters to the assigned values below without triggering checker violations:

min_cke_high_after_reset_deasserted_in_pu_and_res_init_time_ps = 500000
min_reset_pulse_width_in_pu_ps = 200000

To customize the values, the user may set their own customized values and then set the flag “scaled_timing_flag”. The VIP will get configured to the user provided values. As such:

For Discrete Devices:

// cfg handle of the svt_ddr_configuration class

// Pass the cfg to the DDR Discrete Device component by using // the config_db mechanism.

cfg.timing_cfg.min_cke_high_after_reset_deasserted_in_pu_and_res_init_time_ps = 500000;

cfg.timing_cfg.min_reset_pulse_width_in_pu_ps = 200000;

cfg.timing_cfg. tPW_RESET_ps = 100000;

cfg.timing_cfg.scaled_timing_flag = 1;

For DIMM Models:

// dimm_cfg is handle of svt_ddr_dimm_configuration

foreach(dimm_cfg.data_lane_cfg[i]) begin

  foreach(dimm_cfg.data_lane_cfg[i].rank_cfg[j]) begin

    dimm_cfg.data_lane_cfg[i].rank_cfg[j].timing_cfg.min_cke_high_after_reset_deasserted_in_pu_and_res_init_time_ps = 500000;

    dimm_cfg.data_lane_cfg[i].rank_cfg[j].timing_cfg.min_reset_pulse_width_in_pu_ps = 200000;

    dimm_cfg.data_lane_cfg[i].rank_cfg[j].timing_cfg.tPW_RESET_ps = 100000;

    dimm_cfg.data_lane_cfg[i].rank_cfg[j].timing_cfg.scaled_timing_flag = 1;

  end

end

Authored by Nasib Naser

You can learn more about Synopsys Memory VIP here.

Posted in DDR, LPDDR, Memory, Processor Subsystems | No Comments »

Webinar: Accelerating Verification Closure with PCIe Gen4 VIP

Posted by VIP Experts on August 11th, 2015

In a recent post, Paul Graykowski introduced Synopsys VIP for PCIe Gen4.

To dive deeper into the verification closure process, you can now register for our Webinar on August 14th here.

Today’s PCIe verification engineers have to tradeoff between verification completeness and shrinking to market complicated even further with the new Gen4 specification. Synopsys VC VIP for PCIe, fully compliant to latest version of the Gen4 specification, can solve the riddle of completing verification while keeping with the tight schedules.

This webinar will highlight enhancements to the PCIe specifications (Gen 1, 2, 3 and 4) as reported by PCI-SIG, and provide an overview of the complete PCIe Solution offered by Synopsys – Controller, PHY and VIP.  It will then dive deeper into Synopsys Verification IP offering, including Test Suites, built-in error injection, passive monitor, and it will also touch on NVMe support. We will conclude with a demo using Verdi Protocol Analyzer to demonstrate advance features for debugging complex verification scenarios.

Register
Web event: Learn How to Accelerate Verification Closure with PCIe Gen4 VIP
Date: August 19, 2015
Time:10:00 AM PDT

Posted in Data Center, Debug, Methodology, PCIe | No Comments »

Introducing Synopsys VIP for PCIe Gen4

Posted by VIP Experts on August 4th, 2015

Here, Paul Graykowski, Corporate Applications Engineer at Synopsys, describes what our Verification IP for PCIe Gen4 can do for you.

Posted in Data Center, Debug, Methodology, PCIe, SystemVerilog, UVM | No Comments »

Increase Productivity with Synopsys Memory VIP

Posted by VIP Experts on July 28th, 2015

In this video, you will learn how to increase productivity with Synopsys Memory VIP.

You can learn more about our VIPs at Verification IP Overview.

If you are interested in a hands-on workshop in your area, check out our Memory Verification IP Workshops.

Posted in DDR, Debug, DFI, eMMC, Flash, HBM, HMC, LPDDR, Memory, Methodology, ONFi, UFS, UVM | No Comments »

SoC Leaders Verify with Synopsys: DAC 2015 Verification Luncheon

Posted by VIP Experts on July 21st, 2015

Featuring speakers from Altera, AMD, ARM, Cavium and Freescale

During DAC 2015, Synopsys hosted a luncheon event at DAC in San Francisco, CA.

DAC2015-Verification-panel

Michael Sanie, senior director of verification marketing at Synopsys kicked things off by highlighting the Synopsys Verification Continuum and several key next-generation technologies that are in production and address the need to “Shift-Left” for faster time-to-market. These technologies include Verification Compiler, a broad Verification IP portfolio, the industry’s fastest emulation system ZeBu Server-3, and Verdi, the industry’s de facto SoC debug environment.

Later, a panel of SoC industry experts from Altera, AMD, ARM, Cavium and Freescale shared viewpoints on managing the growing verification complexity and how their leading SoC design teams have achieved success by collaborating with Synopsys.

Carlos Velasco, senior manager, SoC Design Verification Group at Altera described the challenges of verifying and debugging their SoC FPGA. He described their system verification environment, the need for verifying their configuration architecture and SoC Topology, and how Synopsys’ native SystemVerilog technology with full UVM support along with a full range of Verification IP has served them well.

Alex Starr, fellow & pre-silicon solutions architect at AMD painted a picture about rethinking the cost of verifcation. He talked about verification complexity; the importance of methodology; and how emulation with ZeBu and Verdi facilitate hardware-software debug.

Alan Hunter, senior principal design engineer at ARM described the shift-left they have been able to achieve for over 17 years working closely with Synopsys. He described statistical methods, IP-focused system verification, debug and low power verification technologies.

Jim Ellis, director of engineering at Cavium described how they have been addressing the unique verification challenges presented by their ThunderX ARM Processors.  He talked about how they were able to shift-left with virtualization, IP and VIP reuse, standardizing their verification flow with VCS, UVM and incorporating Cerititude and VC Formal into their flow.

Robert Oshana, director of software R&D, Digital Networking at Freescale talked about how reference software has been growing a lot faster than Moore’s Law prediction, and how emulating with ZeBu has supported them in their hardware-software debug flow.

Sign up here to view the videos. You can learn more about our VIPs at Verification IP Overview.

Posted in Debug, Methodology, Mobile SoC, Processor Subsystems, Success Stories, SystemVerilog, UVM | Comments Off

Bernie DeLay @ EDACafe on the Value of SystemVerilog, UVM-based VIP

Posted by VIP Experts on June 30th, 2015

Here, Synopsys R&D Director, Bernie DeLay, talks to EDACafe on the value of native SystemVerilog and UVM support in our VIP titles. He describes how our memory and protocol VIP have been built debug-friendly with Protocol Analyzer, and support constraint random verification for full functional coverage with back-annotation to executable verification plans.

EDACafe-Bernie-DeLay

You can learn more about our VIPs at Verification IP Overview.

Posted in AMBA, DDR, Debug, DesignWare, Ethernet, HDMI, LPDDR, Memory, Methodology, PCIe, SystemVerilog, Test Suites, USB, UVM | Comments Off

Verifying MIPI interfaces in SoCs

Posted by VIP Experts on June 23rd, 2015

It is estimated that every smartphone now uses some aspect of the MIPI standards. Last year, one billion phones, and about 6 to 7 billion phone ICs, included a MIPI interface of some sort. MIPI interfaces, especially for cameras and displays, have spread beyond the mobile world into other markets, such as automotive, industrial, medical, the IoT and the digital home/office.

MIPI-System

MIPI interfaces make it easier to design complex smartphone SoCs. However, verifying that they are working correctly provides little differentiating value for the end product. The challenge for design and verification teams, therefore, is to implement robust verification environments for MIPI-based designs as efficiently as possible. Developing in-house verification IP (VIP) and test-benches can be costly and time-consuming, especially if they are to exercise the complex traffic patterns, corner cases, errors and exceptions of the more advanced MIPI interfaces. This strategy also puts the verification team at risk of false or missed failures, from poorly implemented or maintained VIP, and may limit VIP reusability from the block to the SoC level.

It may be better to acquire MIPI VIP and testbenches from a commercial provider that can offer a common look, feel, and use model for all VIP and test-benches and so reduce the time it takes the verification team to learn their use. Users of such VIP should also benefit from the fact the VIP has been tried out in multiple contexts and so will model the MIPI protocols, corner cases and error states comprehensively. Commercial VIP is also likely to have been optimized for performance on multiple simulators, and may be delivered with various debug aids.

Since MIPI interface standards are hierarchical, with the more complex interfaces using aspects of the simpler interfaces, MIPI VIP and verification testbenches tend to have a number of common features:

  • A requirement to both drive the device under test (DUT) and capture its output
  • The ability to drive the VIP or the DUT from the application side, in cases in which the VIP is acting as a transmitter to the DUT
  • Reusable data-integrity scoreboarding, so that data-streams can be compared before and after the interface under test
  • Access to the programming registers of the DUT through a configurable interface
  • Configurability and customization capabilities
  • Reusability of the entire verification environment

Synopsys-MIPI-compliance-test-suite

General Schematic of MIPI Compliance Test Suite

You can learn more about how these common elements recur throughout a suite of MIPI VIP and test-benches, and the way in which more complex MIPI protocols build on lower-level blocks in this article.

There are a lot of common factors in these approaches to verifying MIPI interfaces. IP blocks need to be exercised with a robust set of protocol checks, corner cases, error injection and functional-coverage models to ensure that they comply with the protocols. The VIP and related testbenches need to be kept up-to-date with rapidly evolving specifications and bug fixes. And the verification needs to be rigorous, especially for lower-level blocks such as the PHYs, because more complex interfaces such as UFS rely on them.

Synopsys offers a comprehensive portfolio of VIP for MIPI interfaces, and application using MIPI interfaces, which meets these criteria and offers a common user experience. The portfolio supports the latest versions of the MIPI specifications, and offers comprehensive test suites with functional coverage models, with protocol-aware debug to reduce debug turnaround time. Finally, the VIP blocks are written in SystemVerilog for use on a wide range of simulators.

You can learn more about our comprehensive support for MIPI titles at VC Verification IP for MIPI.

Authored by Nitin Agarwal

Posted in Methodology, MIPI, UFS | Comments Off

Hands-on Memory Verification IP Workshops

Posted by VIP Experts on June 16th, 2015

Synopsys Memory Verification IP is modeled natively in SystemVerilog and supports the common verification standard UVM. Our models support 100% of the memory standard as specified by JEDEC.

Now you can take a deep dive into our VIP solutions at no cost with a hands-on workshop. The workshop will highlight and demonstrate how you can achieve rapid verification convergence on your JEDEC DDR based designs. Through a combination of lecture and lab, we’ll show you how to achieve success in verifying complex SoC designs that include advanced memory protocols such as DDR4/3, LPDDR4/3, UFS, eMMC, HBM, HMC and more.

You and your colleagues can register now for a workshop near you:

Schedule:  9:00 a.m. – 2:30 p.m.

Agenda

  • Synopsys Verification IP for DDR Memory Protocols
  • Testbench Configuration made easy with Memory VIP
  • Lab 1: Memory VIP Configurations
  • Lab 2: Memory VIP Checkers and Monitors
  • Lunch (provided by Synopsys)
  • Lab 3: Memory VIP Debug with Verdi
  • Lab 4: Memory VIP Coverage with Verdi

More Information
Please contact us by email at vipworkshops@synopsys.com to request a hands-on workshop in your area. Attendance at this event is free, and registration is required. Seating is limited and not all registrations will be accepted. All events are subject to cancellation. For more details, see Memory VIP Workshops.

Posted in DDR, eMMC, HBM, HMC, LPDDR, Memory, Methodology, ONFi, UFS | Comments Off