Russian MPs on Tuesday passed in the final third reading controversial legislation banning "propaganda" of remaining childless, the latest measure targeting what Moscow depicts as Western liberal ideas.

A state-funded English-language broadcaster in Taiwan removed a video of one of its journalists calling US President-elect Donald Trump a "convicted felon", after the Taipei government said the incident was "very serious".

The Supreme Court is scheduled to pronounce its verdict on Wednesday on pleas seeking framing of guidelines on the demolition of properties in the country.

The US Senate's Democratic majority began a crusade on Tuesday to confirm as many new federal judges nominated by President Joe Biden as possible to avoid leaving vacancies that Republican Donald Trump could fill after taking office on Jan. 20.

Signal has been updated with Call Links, a feature that enables users to initiate a group call with multiple participants without the need to form a separate group chat. Additional updates include a "raise hand" button, emoji reactions, and a dedicated calls tab on Signal.

A study from NYU reveals that kidney and nerve cells can perform memory-like functions, suggesting memory capabilities are not restricted to the brain. By replicating a spaced learning process, scientists observed memory gene activation in these non-neural cells, expanding possibilities for enhancing learning and treating memory-related health issues.

Amjad Khan worked in over 132 films in a career spanning nearly two decades

Hemansh Kohli wore a green kurta at his mehendi ceremony

The Trunk will premiere on November 29 on Netflix

On a bright Sunday afternoon, two men walked door to door through a Forsyth County, Georgia, neighborhood on a mission to get out the vote for Democrats.

The foundation of Delaware’s democracy is its General Assembly. A body that has governed both the colony and state of Delaware for over three hundred years, it has been the voice of the people in our government and has affected almost every aspect of our lives. Dr. Carol Hoffecker’s “Democracy in Delaware” discusses the role […]

The Office of Veterans Services and the Delaware Commission of Veterans Affairs have scheduled two events in observance of Memorial Day. As in previous years, OVS and the Commission will host ceremonies on separate days. The first will take place on Saturday, May 28, 2022, at the Delaware Veterans Memorial Day Cemetery in Bear. The […]

The Office of Veterans Services (OVS) and the Delaware Commission of Veterans Affairs (DCVA) have scheduled two events in observance of Memorial Day. As in previous years, OVS and DCVA will host ceremonies on separate days. The first will take place on Saturday, May 27, 2023, at the Delaware Veterans Memorial Ceremony in Bear, Delaware. […]

New lobby exhibit celebrates “things that aren’t there anymore” Do you remember rocking at the Stone Balloon; enjoying a muskrat meal at The Wagon Wheel; or having a shopping spree at Wanamaker’s?  If you don’t the Delaware Public Archives does. Starting in April 2024, the DPA will kick off a celebration and remembrance of things […]

WILMINGTON, Del. – Governor John Carney on Tuesday released the following statement on the Christina Board of Education’s vote to approve a Memorandum of Understanding to invest in Christina’s Wilmington schools: “Thank you to the members of the Christina Board for their important vote tonight on this MOU. This is just a first step, but […]

In observance of Worker’s Memorial Day, the Delaware Department of Labor’s (DOL) Office of Safety and Health Consultation is proud to announce the launch of SafeDE (pronounced Safe-DEE-EEE). This groundbreaking initiative signifies our dedication to enhancing workplace safety throughout Delaware, honoring the memory of workers who have tragically lost their lives on the job. SafeDE […]

The Delaware Department of Agriculture (DDA) is accepting applications through May 1, 2023, for a new Poultry House Demolition Assistance Program announced today. The program provides cost-share assistance to remove old poultry houses past their useful life.

DOVER, Del. (April 22, 2024) – The Delaware Forest Service hosted the Daughters of the American Revolution (DAR), Col. John Haslet Chapter in Dover, and other volunteers to establish a memorial plot dedicated to former State Forester Walter F. Gabel, who served in this role from 1974 to 1991. “We are excited about this DAR […]

Friday, May 15 is Peace Officers Memorial Day. On this day we pay tribute to peace officers across our country who have died, or who have been disabled in the line of duty. In accordance with federal law (36 U.S.C. 175) and a proclamation issued by President Trump, Governor Carney requests that the Delaware and […]

On Memorial Day, we pay tribute to those fallen heroes who have died while protecting our country. To honor the dedication and service of all of our service members Governor Carney requests that the proper protocol for the U.S. Flag Code be followed this Memorial Day. Flags are to be lowered to half-staff on Monday […]

Everyday across Delaware, thousands of firefighters serve their communities and protect the public by responding to not only fires but almost any emergency situation. Sunday, October 4 has been recognized by Congress as the day US and State flags are to be flown at half-staff in recognition of the National Fallen Firefighters Memorial Day. Governor […]

President Biden ordered flags at all U.S. government buildings and facilities to be flown at half-staff until sunset on February 26, 2021 in memory of the more than 500,000 Americans who have died from COVID-19. In concurrence with the President’s order, Governor Carney has ordered both the U.S. and Delaware flags at state buildings and […]

In recognition of Memorial Day, President Biden has proclaimed May 31, 2021, as a day of prayer for permanent peace, and designated the hour of 11:00 AM as a time when we might collectively unite in prayer and reflection. President Biden has also asked that all Americans observe the National Moment of Remembrance beginning at […]

Governor Carney and Lieutenant Governor Hall-Long join family, friends and Delawareans across our state in paying tribute to the extraordinary life and service of Second Lieutenant George M. Johnson. In recognition, the Delaware flag will be lowered to half-staff on Saturday, October 2, 2021.

In observance of the 40th National Fallen Firefighters Memorial Service and in accordance with Public Law 107-51, Governor Carney has ordered both the American and Delaware flags be lowered to half-staff on Sunday, October 3, 2021 from sunrise to sunset.

As a mark of respect for the passing of General Colin L. Powell and in recognition of his tremendous life of service to this nation, President Biden has ordered that the U.S. flag be immediately flown at half-staff until sunset on October 22, 2021. In concurrence with the President’s order, Governor Carney has ordered both […]

In recognition of Chief Pridemore’s service to the State of Delaware, Governor Carney has ordered the Delaware flag at state buildings and facilities be flown at half-staff until sunset on March 15, 2022.

As a mark of respect for the passing of Madeleine Korbel Albright, the first female U.S. Secretary of State, and in recognition of her tremendous life of service to this nation, President Biden has ordered that the U.S. flag be immediately flown at half-staff until sunset on March 27, 2022. In concurrence with the President’s order, Governor Carney has ordered both the U.S. and Delaware flags at state buildings and facilities be flown at half-staff.

NEW CASTLE (Dec. 22, 2021) Forty-eight individuals and 13 groups will be honored with the 2021 Governor’s Outstanding Volunteer Award during a virtual ceremony to be held at 7 p.m. Jan. 17, 2022. The recipients will be recognized for significant contributions, engagement and impact in diverse service activities. Throughout the month of December, staff members […]

NEW CASTLE (Jan. 10, 2022) — Due to challenges presented by recent increases in COVID-19 cases across the state, the State Office of Volunteerism has made the difficult decision to postpone the Virtual Ceremony honoring the 48 individuals and 13 groups selected to receive the 2021 Governor’s Outstanding Volunteer Award. The ceremony will now air […]

Ten individuals and six groups will be honored with the 2022 Governor’s Outstanding Volunteer Awards during a ceremony to be held Dec. 1 at the Executive Banquet & Conference Center in Newark. The award recipients will be recognized for exceptional contributions and outstanding dedication to service and volunteerism in Delaware.

NEW CASTLE (May 30, 2023) – Governor John Carney will present the 2023 Governor’s Youth Volunteer Service Awards to 11 individuals, four groups, and five emerging leaders during a June 21 ceremony to recognize their remarkable service to Delaware. These prestigious awards acknowledge the significant impact that young volunteers make in their communities, inspiring others […]

The Latin American Community Center (LACC) presents a unique art contest and invites participants to explore addiction through artistic expression. ArtAddiction, a juried art competition hosted by the LACC’s Prevention Promoters Program, seeks to explore addiction, recovery, and mental health through artistic expression. This year’s theme, “Change IS A Process,” has categories that include painting, drawing, […]

NEW CASTLE – Governor John Carney will present the 2024 Governor’s Volunteer Service Awards to 17 individuals, six groups, seven emerging youth leaders, and one corporation during an April 4 ceremony to recognize their exceptional volunteer service. The ceremony, to be held at the Modern Maturity Center in Dover, will celebrate significant contributions to communities […]

Emojis are showing up in our data. Here's what you need to know when working with emojis in your SAS code.

The post How to work with emojis in SAS appeared first on The SAS Dummy.

Strategic enhancements to the pedestrian safety campaign leverage grassroots influence and broad communications reach throughout Delaware DOVER, DE. (May 27, 2021) — This Memorial Day, The Delaware Office of Highway Safety (OHS) is bringing back its “Walk Smart, Arrive Alive” campaign — with a few additions designed to expand its reach and impact on some of the […]

Flags are ordered to fly half-staff until sunset on May 15th.

The Office of Veterans Services (OVS) and the Delaware Commission of Veterans Affairs (DCVA) have scheduled two events in observance of Memorial Day. As in previous years, OVS and DCVA will host ceremonies on separate days. The first will take place on Saturday, May 25, 2024, at the Delaware Veterans Memorial Ceremony in Bear, Delaware. […]

A Florida appellate court has upheld AG Kathy Jennings’ authority to continue advocating for funding for Nemours Children’s Hospital. “The consequences of this case could be a game changer for kids in Delaware,” said AG Jennings. “Anyone whose child has received care at Nemours Hospital understands how exceptional they are. That’s the hallmark of A.I. […]

The Delaware State Fire Commission is thrilled to announce the Groundbreaking Ceremony for our new building scheduled for Friday, September 6, 2024, at 11:00 am. The ceremony will be held at the Delaware Fire Service Center, 1463 Chestnut Grove Road, Dover, Delaware. “Our long-awaited new building will replace the current one attached to the rear […]

On Friday, September 6, 2024, the Delaware State Fire Prevention Commissioners held their groundbreaking ceremony for their new building. The Commissioners wanted to express their sincere gratitude for everyone’s presence at the groundbreaking ceremony. The support and encouragement mean a great deal to us, and we are truly thankful for all who attended and participated […]

Read the in depth Review of CORSAIR DOMINATOR PLATINUM RGB First Edition DDR5 DRAM Memory Kit PC Components. Know detailed info about CORSAIR DOMINATOR PLATINUM RGB First Edition DDR5 DRAM Memory Kit configuration, design and performance quality along with pros & cons, Digit rating, verdict based on user opinions/feedback.

1. BREAKING| 'Bulldozer Reminds Of Lawlessness' : Supreme Court Says Properties Can't Be Demolished Merely...  Live Law - Indian Legal News
2. "Officials To Pay From Salary": Top Court Guidelines On 'Bulldozer Justice'  NDTV
3. ‘Heavens won’t fall on authorities if they hold their hands for some period’: SC sets pan India guidelines against bulldozer action  The Financial Express
4. Executive Can't Become Judge, Pronounce Guilt Of Persons & Punish Them By Demolishing Their Properties :...  Live Law - Indian Legal News
5. ‘Officials will pay for demolitions from their salary’: 5 Key SC observations on ‘chilling’ side of ‘bulldozer justice’  Mint

PCI-SIG DevCon 2024 – 32^nd Anniversary

For more than a decade, Cadence has been well-known in the industry for its strong commitment and support for PCIe technology. We recognize the importance of ensuring a robust PCIe ecosystem and appreciate the leadership PCI-SIG provides. To honor the 32^nd anniversary of the PCI-SIG Developer’s Conference, Cadence is announcing a complete PCIe 7.0 IP solution for HPC/AI markets.

Why Are Standards Like PCIe So Important?

From the simplest building blocks like GPIOs to the most advanced high-speed interfaces, IP subsystems are the lifeblood of the chipmaking ecosystem. A key enabler for IP has been the collaboration between industry and academia in the creation of standards and protocols for interfaces. PCI-SIG drives some of the key definitions and compliance specifications and ensures the interoperability of interface IP.

HPC/AI markets continue to demand high throughput, low latency, and power efficiency. This is fueling technology advancements, ensuring the sustainability of PCIe technology for generations to come. As a close PCI-SIG member, we gain valuable early insights into the evolving specs and the latest compliance standards. PCIe 7.0 specifications and beyond will enable the market to scale, and we look forward to helping our customers build best-in-class cutting-edge SoCs using Cadence IP solutions.

Figure 1. Evolution of PCIe Data Rates (source PCI-SIG)

What’s New This Year at DevCon?

At DevCon ’24, the PCIe 7.0 standard will take center stage, and Cadence is showing off a full suite of IP subsystem solutions for PCIe 7.0 this year.

What Sets Cadence Apart?

At Cadence, we believe in building a full subsystem for our testchips with eight lanes of PHY along with a full 8-lane controller. Adding a controller to our testchip significantly increases the efficiency and granularity in characterization and stress testing and enables us to demonstrate interoperability with real-world systems. We are also able to test the entire protocol stack as an 8-lane solution that encompasses many of the applications our customers use in practice. This approach significantly reduces the risks in our customers’ SoC designs.

Figure 2: Piper - Cadence PHY IP for PCIe 7.0

Figure 3: Industry’s first IP subsystem for PCIe 7.0

Which Market Is This For?

At a time when accelerated computing has gone mainstream, PCIe links are going to take on a role of higher importance in systems. Direct GPU-to-GPU communication is crucial for scaling out complex computational tasks across multiple graphics processing units (GPUs) or accelerators within servers or computing pods. There is a growing recognition within the industry of a need for scalable, open architecture in high-performance computing. As AI and data-intensive applications evolve, the demand for such technologies will likely increase, positioning PCIe 7.0 as a critical component in the next generation of interface IP.

Here's a recent article describing a potential use case for PCIe 7.0.

Figure 4: Example use case for PCIe 7.0

Why Are Optical Links Important?

It takes multiple buildings of data centers to train AI/ML models today. These buildings are increasingly being distributed across geographies, requiring optical fiber networks that are great at handling the increased bandwidth over long distances. However, these optical modules soon hit a power wall where all the budgeted power is used to drive the signal from point A to point B, and there is not enough power left to run the actual CPUs and GPUs. Such scenarios create a need for non-retimed, linear topologies. Linear Pluggable Optics (LPO) links can significantly reduce module power consumption and latency when compared to traditional Digital Signal Processing (DSP) based retimed optical solutions, which is critical for accelerating AI performance. Swapping from DSP-based solutions to LPO results in significant cost savings that help drive down expenditure due to lower power and cooling requirements, but this requires a robust high-performance ASIC to drive the optics rather than retimers/DSP.

To showcase the robustness of Cadence IP, we have demonstrated that our subsystem testchip board for PCIe 7.0 can successfully transmit and receive 128GT/s signals through a non-retimed opto-electrical link configured in an external loopback mode with multiple orders of margin to spare.

Figure 5: Example of ASIC driving linear optics

Compliance Is Key

For PCIe 6.0, the official compliance program has not started yet; this is typical for the SIG where the official compliance follows a few years after the spec is ratified to give enough time for the ecosystem to have initial products ready, and for test and equipment vendors to get their hardware/software up and running. At this time, PCIe Gen6 implementations can only be officially certified up to PCIe 5.0 level (the highest official compliance test suite that the SIG supports). We have taken our PCIe 6.0 IP subsystem solution to the SIG for multiple process nodes, and they are all listed as compliant. You can run this query on the pcisig.com website under the Developers->Integrators list by making the following selections:

Due to space limitations, not all combinations could be tested at the May workshop (e.g., N3 root port) – this will be tested in the next workshop.

Also, the SIG just held an “FYI” compliance event this week to bring together the ecosystem for confidential testing (no results were reported, and data cannot be shared outside without violating the PCI-SIG NDA). We participated in the event with multiple systems and can report that our systems have done quite well. The test ecosystem is not mature yet, and a few more FYI workshops will be conducted before the official compliance for 6.0 is launched. We have collaborated with all the key test vendors for electrical and protocol testing throughout the year. As early as the middle of last year, we were able to provide test cards to all these vendors to demo PCIe 6.0 capabilities in their booths at various events. Many of them recorded these videos, and they can be found online.

• Cadence Subsystem IP for PCIe 6.0: Protocol and Electrical Testing
• Cadence Subsystem IP for CXL Protocol Test Demo
• Cadence Subsystem IP for CXL2.0/3.0 Protocol Test Demo
• Cadence Subsystem IP for PCIe 6.0: Protocol Stack Demo

More at the PCI-SIG Developers Conference

Check us out at the PCI-SIG Developer’s conference on June 12 and 13 to see the following demonstrations:

• Robust performance of Cadence IP for PCIe 7.0 transmitting and receiving 128GT/s signals over non-retimed optics
• Capabilities of Cadence IP for PCIe 7.0 measured using oscilloscope instrumentation detailing its stable electrical performance and margin
• The reliability of Cadence IP for PCIe 6.0 interface using Test Equipment to characterize the PHY receiver quality
• A PCI-SIG-compliant Cadence IP subsystem for PCIe 6.0 optimized for both power and performance

As a leader in PCI Express, Anish Mathew of Cadence will share his valuable insights on an important topic: “Impact of UIO ECN on PCIe Controller Design and Performance,” highlighting the strides made by the Cadence design team in achieving this implementation.

Figure 6: Cadence UIO Implementation Summary

Summary

Cadence showcased PCIe 7.0-ready IP at PCI-SIG Developers Conference 2023 and continues to lead in PCIe IP development, offering complete solutions in advanced nodes for PCIe 7.0 that will be generally available early next year. With a full suite of solutions encompassing PHYs, Controllers, Software, and Verification IP, Cadence is proud to be a member of the PCI-SIG community and is heavily invested in PCIe. Cadence was the first IP provider to bring complete subsystem solutions for PCIe 3.0, 4.0, 5.0, and 6.0 with industry-leading PPA and we are proud to continue this trend with our latest IP subsystem solution for PCIe 7.0, which sets new benchmarks for power, performance, area, and time to market.

The generative AI market is experiencing rapid growth, driven by the increasing parameter size of Large Language Models (LLMs). This growth is pushing the boundaries of performance requirements for training hardware within data centers. For an in-depth look at this, consider the insights provided in "HBM3E: All About Bandwidth". Once trained, these models are deployed across a diverse range of applications. They are transforming sectors such as finance, meteorology, image and voice recognition, healthcare, augmented reality, high-speed trading, and industrial, to name just a few.

The critical process that utilizes these trained models is called AI inference. Inference is the capability of processing real-time data through a trained model to swiftly and effectively generate predictions that yield actionable outcomes. While the AI market has primarily focused on the requirements of training infrastructure, there is an anticipated shift towards prioritizing inference as these models are deployed.

The computational power and memory bandwidth required for inference are significantly lower than those needed for training. Inference engines typically need between 300-700GB/s of memory bandwidth, compared to 1-3TB/s for training. Additionally, the cost of inference needs to be lower, as these systems will be widely deployed not only in data centers but also at the network's edge (e.g., 5G) and in end-user equipment like security cameras, cell phones, and automobiles.

When designing an AI inference engine, there are several memory options to consider, including DDR, LPDDR, GDDR, and HBM. The choice depends on the specific application, bandwidth, and cost requirements. DDR and LPDDR offer good memory density, HBM provides the highest bandwidth but requires 2.5D packaging, and GDDR offers high bandwidth using standard packaging and PCB technology.

The GDDR7 standard, announced by JEDEC in March of this year, features a data rate of up to 192GB/s per device, a chip density of 32Gb, and the latest data integrity features. The high data rate is achieved by using PAM3 (Pulse Amplitude Modulation) with 3 levels (+1, 0, -1) to transmit 3 bits over 2 cycles, whereas the current GDDR6 generation uses NRZ (non-return-to-zero) to transmit 2 bits over 2 cycles.

GDDR7 offers many advantages for AI Inference having the best balance of bandwidth and cost. For example, an AI Inference system requiring 500GB/s memory bandwidth will need only 4 GDDR7 DRAM running at 32Gbp/s (32 data bits x 32Gbp/s per pin = 1024Gb/s per DRAM). The same system would use 13 LPDDR5X PHYs running at 9.6Gbp/s, which is currently the highest data rate available (32 data bits x 9.6Gb/s = 307Gb/s per DRAM).

Cadence stands at the forefront of AI inference hardware support, being the first IP company to roll out GDDR7 PHYs capable of impressive speeds up to 36Gb/s across various process nodes. This milestone builds on Cadence's established leadership in GDDR6 PHY IP, which has been available since 2019. The company caters to a diverse client base spanning AI inference, graphics, automotive, and networking equipment.

While GDDR7 continues to utilize standard PCB board technology, the increased signal speeds seen in GDDR6 (20Gbp/s) and now GDDR7 (36Gb/s) calls for careful attention with the physical design to ensure optimized system performance. In addition to providing the PHY, Cadence also offers comprehensive PCB and package reference design, which are essential in helping customers achieve optimal signal and power integrity (SI/PI) for their systems.

Cadence is dedicated to ensuring customer success beyond just providing hardware. They provide expert support in SI/PI, collaborating closely with customers throughout the design process. This approach ensures that customers can benefit from Cadence's expertise in navigating the complexities of high-speed design and achieving optimal performance in their AI inference systems.

As the AI market continues to advance, Cadence remains at the forefront by offering a comprehensive memory IP portfolio tailored for every segment of this dynamic market. From DDR5 and HBM3E, which cater to the intensive demands of training in servers and high-performance computing (HPC), to LPDDR5X designed for low-end inference at the network edge and in consumer devices, Cadence's offerings cover a wide range of applications.

Looking to the future, Cadence is dedicated to innovating at the forefront of memory system performance, ensuring that the evolving needs of AI training and inference are met with the highest standards of excellence. Whether it's pushing the boundaries with GDDR7 or exploring new technologies, Cadence is dedicated to driving the AI revolution forward, one breakthrough at a time.

Learn more about Cadence GDDR7 PHY

Learn more about Cadence Simulation VIP for GDDR7.

I am trying to remove the cdn_loop_breaker cells from the netlist. 
When I tried the below 2 things, genus synthesis tool removing the cdn_loop_breaker cells but while connecting the cdn_loop_breaker cell input to its proper connection, its somehow misleading the connections

Things i tried:
1.  remove_cdn_loop_breaker -instances *cdn_loop_breaker*
then i just ran remove_cdn_loop_breaker  comand without the -instances switch
2. remove_cdn_loop_breaker  
     
both of the above things are not providing the proper connections after removing the loop_breaker_cells

can anyone suggest the best possible workaround for this please?

Hi,all

  I want to remove some Tests form adexl automatically,there have any function to achieve that?

I was trying to remove the cdn_loop_breaker cells from the netlist. 
When I tried the below 2 things, it removing the cdn_loop_breaker cells but while connecting the cdn_loop_breaker cell input to its proper connection, its somehow misleading the connections

Things i tried:
1.  remove_cdn_loop_breaker -instances *cdn_loop_breaker*
then i just ran remove_cdn_loop_breaker  comand without the -instances switch
2. remove_cdn_loop_breaker  
     
both of the above things are not providing the proper connections after removing the loop_breaker_cells

With the DRAM fabrication advancing from 1x to 1y to 1z and further to 1a, 1b and 1c nodes along with the DRAM device speeds going up to 8533 for Lpddr5/8800 for DDR5, Data integrity is becoming a really important issue that the OEMs and other users have to consider as part of the system that relies on the correctness of data being stored in the DRAMs for system to work as designed.

It’s a complicated problem that requires multiple ways to deal with it.

Traditionally one of the main approaches to deal with data errors is to rely on the ECC. ECC requires additional memory storage in which the ECC codes will calculated and stored at the time of memory write to DRAM. These codes will be read back along with the memory data during to the reads and checked against the data to make sure that there are no errors. Typical ECC schemes use Hamming code that provide for single bit error correction and double bit error detection per burst. Also, while several of previous generation of DRAM required Host to keep aside system memory for ECC storage latest DRAMs like Lpddr5 and DDR5 support on die ECC as part of the normal DRAM function that can be enabled using mode registers. DDR5 further requires Host to run through an ECC Error Check and Scrub (ECS) cycle on an average every tECSint time (Average Periodic ECS Interval) to prevent data errors.

Not meeting the DRAM Refresh requirement is a major reason that can lead to loss of data. This could be challenging as the PVT variation can cause the refresh requirement to change over time. Putting the DRAM in Self Refresh mode can help off-loading Refresh tracking responsibilities to DRAM but may prevent Host to do other scheduling optimizations and should be carefully considered.

Some of the other things that can affect the DRAM data are

1. Row hammer where same or adjacent rows are activated again and again leading to loss or changing of data contents in the rows that has not being addressed. Latest DRAMs like Lpddr5/Ddr5 support Refresh Management (including DRFM and ARFM) that allows the Host to compensate for these problems by issuing dedicated RFM commands helping DRAMs deals with potential Data loss issues arising out of Row hammer attacks.
2. Device temperature is another important factor that the Host needs to be aware of and if the application requires DRAM to operate at elevated temperature. The user needs to check with DRAM Vendor on the temperature range that DRAM can still operate. Data integrity at thresholds greater than certain temperature is not assured regardless of refresh rate unless DRAM is manufactured to withstand that.
3. Loss of power to DRAM will cause DRAM to lose all its contents. If this is a real concern for the system designer, they should consider using NVDIMM-N devices which has an onchip controller and a power source which is just enough to allow the DRAM contents to be copied into a backup non-volatile memory before power is lost. When the power is stored back, the stored memory contents in the non-volatile memory will be written back to the DRAM and system can continue to operate as it was before the power loss event occurred.

For transmissions and manufacturing errors DRAMs support additional features like CRC, DFE, Pre-Emphasis and PPR which will be covered in the next blog.

Cadence MMAV VIPs for DDR5/DDR5 DIMM and LPDDR5 are compressive VIP solutions and supports all of the above-listed Data integrity features including support for ECC error injection and SBE correction/DBE detection to assist with the verification challenges dealing with data integrity issues.

More information on Cadence DDR5/LPDDR5 VIP is available at Cadence VIP Memory Models Website.

Shyam 

The application of real-time data processing or responsiveness is crucial, such as in high-performance computing, data centers, or applications requiring low-latency data transfers. It enables efficient use of PCIe bandwidth and resources by intelligently managing memory write operations based on system dynamics and workload priorities. By effectively leveraging Deferrable Memory Write [DMWr], Devices can achieve optimized performance and responsiveness, aligning with the evolving demands of modern computing applications.

What Is Deferrable Memory Write?

Deferrable Memory Write (DMWr) ECN introduced this new memory transaction type, which was later officially incorporated in PCIe 5.0 to CXL2.0. This enhanced type of memory transaction is Deferrable Memory Write [DMWr], which flows as another type of existing Read/Write memory transaction; the major difference of this Deferrable Memory Write, where the Requester attempts to write to a given location in Memory Space using the non-posted DMWr TLP Type, it Postponing their completion of memory write transactions to improve overall system efficiency and performance, those memory write operation can be delay or deferred until other priority task complete.

The Deferrable Memory Write (DMWr) requires the Completer to return an acknowledgment to the Requester and provides a mechanism for the recipient to defer (temporarily refuse to service) the Request.

DMWr provides a mechanism for Endpoints and hosts to choose to carry out or defer incoming DMWr Requests. This mechanism can be used by Endpoints and Hosts to simplify the design of flow control, reduce latency, and improve throughput. The Deferrable Memory writes TLP format in Figure A.

(Fig A) Deferrable Memory writes TLP format.

Example Scenario

Here's how the DMWr works with a simplified example: Imagine a system with an endpoint device (Device A) and a host CPU (Device B). Device B wants to write data to Device A's memory, but due to varying reasons such as system bus congestion or prioritization of other transactions, Device A can defer the completion of the memory write request. Just follow these steps:

1. Initiation of Memory Write: Device B initiates a memory write transaction to Device A. This involves sending the memory write request along with the data payload over the PCIe physical layer link.
2. Acknowledgment and Deferral: Upon receiving the memory write request, Device A acknowledges the transaction but may decide to defer its completion. Device A sends an acknowledgment (ACK) back to Device B, indicating it has received the data and intends to complete the write operation but not immediately.
3. Deferred Completion: Device A defers the completion of the memory write operation to a later, more opportune time. This deferral allows Device A to prioritize other transactions or optimize the use of system resources, such as memory bandwidth or processor availability.
4. Completion and Response: At a later point, Device A completes the deferred memory write operation and sends a completion indication back to Device B. This completion typically includes any status updates or additional information related to the transaction.

Usage or Importance of DMWr

Deferrable Memory Write usage provides the improvement in the following aspects:

• Reduced Latency: By deferring less critical memory write operations, more critical transactions can be processed with lower latency, improving overall system responsiveness.
• Improved Efficiency: Optimizes the utilization of system resources such as memory bandwidth and CPU cycles, enhancing the efficiency of data transfers within the PCIe architecture.
• Enhanced Performance: Allows devices to manage and prioritize transactions dynamically, potentially increasing overall system throughput and reducing contention.

Challenges in the Implementation of DMWr Transactions

The implementation of deferrable memory writes (DMWr) introduces several advancements and challenges in terms of usage and verification:

1. Timing and Synchronization: DMWr allows transactions to be deferred, complicating timing requirements or completing them within acceptable timing windows to avoid protocol violations. Ensuring proper synchronization between devices becomes critical to prevent data loss or corruption.
2. Protocol Compliance: Verification must ensure compliance with ECN PCIe 6.0 and CXL specifications regarding when and how DMWr transactions can be initiated and completed.
3. Performance Optimization: While DMWr can improve overall system performance by reducing latency, verifying its impact on system performance and ensuring it meets expected benchmarks is crucial.
4. Error Handling: Handling errors related to deferred transactions adds complexity. Verifying error detection and recovery mechanisms under various scenarios (e.g., timeout during deferral) is essential.

Verification Challenges of DMWr Transactions

The challenges to verifying the DMWr transaction consist of all checks with respect to Function, Timing, Protocol compliance, improvement, Error scenario, and security usage on purpose, as well as Data integrity at the PCIe and CXL.

1. Functional Verification: Verifying the correct implementation of DMWr at both ends of the PCIe link (transmitter and receiver) to ensure proper functionality and adherence to specifications.
2. Timing Verification: Validating timing constraints associated with deferring writes and ensuring transactions are completed within specified windows without violating protocol rules.
3. Protocol Compliance Verification: Checking that DMWr transactions adhere to PCIe and CXL protocol rules, including ordering rules and any restrictions on deferral based on the transaction type.
4. Performance Verification: Assessing the impact of DMWr on overall system performance, including latency reduction and bandwidth utilization, through simulation and testing.
5. Error Scenario Verification: Creating and testing scenarios to verify error handling mechanisms related to DMWr, such as timeouts, retries, and recovery procedures.
6. Security Considerations: Assessing potential security vulnerabilities related to DMWr, such as data integrity risks during deferred transactions or exposure to timing-based attacks.

Major verification challenges and approaches are timing and synchronization verification in the context of implementing deferrable memory writes (DMWr), which is crucial due to the inherent complexities introduced by deferred transactions. Here are the key issues and approaches to address them:

Timing and Synchronization Issues

1. Transaction Completion Timing:
   • Issue: Ensuring deferred transactions are completed within the specified time window without violating protocol timing constraints.
   • Approach: Design an internal timer and checker to model worst-case scenarios where transactions are deferred and verify that they are complete within allowable latency limits. This involves simulating various traffic loads and conditions to assess timing under different scenarios.
2. Ordering and Dependencies:
   • Issue: Verifying that transactions deferred using DMWr maintain the correct ordering and dependencies relative to non-deferred transactions.
   • Approach: Implement test scenarios that include mixed traffic of DMWr and non-DMWr transactions. Verify through simulation or emulation that dependencies and ordering requirements are correctly maintained across the PCIe link.
3. Interrupt Handling and Response Times:
   • Issue: Verify the handling of interrupts and ensure timely responses from devices involved in DMWr transactions.
   • Approach: Implement test cases that simulate interrupt generation during DMWr transactions. Measure and verify the response times to interrupts to ensure they meet system latency requirements.

In conclusion, while deferrable memory writes in PCIe and CXL offer significant performance benefits, their implementation and verification present several challenges related to timing, protocol compliance, performance optimization, and error handling. Addressing these challenges requires rigorous testing and testbench of traffic, advanced verification methodologies, and a thorough understanding of PCIe specifications and also the motivation behind introducing this Deferrable Write is effectively used in the CXL further. Outcomes of Deferrable Memory Write verify that the performance benefits of DMWr (reduced latency, improved throughput) are achieved without compromising timing integrity or violating protocol specifications.

In summary, PCIe and CXL are complex protocols with many verification challenges. You must understand many new Spec changes and consider the robust verification plan for the new features and backward compatible tests impacted by new features. Cadence's PCIe 6.0 Verification IP is fully compliant with the latest PCIe Express 6.0 specifications and provides an effective and efficient way to verify the components interfacing with the PCIe 6.0 interface. Cadence VIP for PCIe 6.0 provides exhaustive verification of PCIe-based IP and SoCs, and we are working with Early Adopter customers to speed up every verification stage.

More Information

• For more info on how Cadence PCIe Verification IP and TripleCheck VIP enable users to confidently verify PCIe 6.0, see our VIP for PCI Express, VIP for Compute Express Link, and TripleCheck for PCI Express
• See the PCI-SIG website for more details on PCIe in general and the different PCI standards.