Hi everyone. 

I'm very a new cadence user. I'm not good at using it and quite lost in finding a way to get the results. With the topic, I would like to ask you for some suggestions to improve my cadence skills.

I have some digital decision logic. Some are combinational logic, some are sequential logic that I would like to import or generate random input combination to the inputs of my decision logic to get the maximum, minimum, and average delay power dissipation and area when feeding the different input combination.

My logic has 8-bit, 16-bit, and 32-bit input. The imported data tends to be decimal numbers.

I would like to ask you:

- which tool(s) are the most appropriate to import and feed the different combination to my decision logic?

- which tool is the most appropriate to synthesis with different number of input? - I have used Genus Synthesis Solution so far. However with my skill right now I can only let Genus synthesize my Verilog code one setup at a time. I'm not sure if I there is anyway I can feed a lot of input at a time and get those results (min, max, average of delay, power dissipation and area)

- which language or scripts I should pick up to use and achieve these results?

-where can I find information to solve my problem? which information shall I look for?

Thank you so much for your time!!

Best Regards

i want to read from text file two values  on two ports , i wrote  that  code, and i have that error that shown in the image below . and also the data in text file is shown as screenshot

module read_file (a,b);

electrical a,b;
integer in_file_0,data_value, valid, count0,int_value;

analog begin
@(initial_step) begin
in_file_0 = $fopen("/home/hh1667/ee610/my_library/read_file/data2.txt","r");

valid = $fscanf (in_file_0, "%b,%b" ,int_value,count0);
end

V(a) <+ int_value;
V(b) <+ count0;

end

endmodule

I am trying to understand the Linting process. I know that mainly JasperGold is the tool for this purpose. Though I think JasperGold is more suited for later stages of the design. As a RTL Design Engineer, I want to make sure that if another tool has the capability of doing Linting earlier in the flow. for example, does Xcelium, Genus or Confomal support linting. I have seen some contradicting information online regarding this topic, though I can't find anything related to Linting on any of these tools.

Thanks

It has become challenging to ensure that the designs are complete, correct, and adhere to necessary coding rules before handing them off for RTL verification and implementation. RTL Designer Signoff Solution from Cadence helps the user identify RTL bugs at a very early development stage, saving a lot of effort and cost for the design and verification team. Our reputed customers have confirmed that using RTL signoff for their design IP helped save up to 4 weeks and reduce the late-stage RTL changes by up to 80%.(read more)

New IC packaging workflows in Cadence Allegro X layout tools allow you to follow a guided path from starting a design through final manufacturing. The path is there to ensure that you don’t miss steps and perform actions in the optimal order. W...(read more)

Starting SPB 23.1, Allegro Package Designer Plus (APD+) has been rebranded as Allegro X Advanced Package Designer (Allegro X APD).

The splash screen for Allegro X APD will appear as shown below, instead of showing APD+ 2023:

For the Windows Start menu in 23.1, it will display as Allegro X APD 2023 instead of APD+ 2023, as shown below

23.1 Start menu 

In the Product Choices window for 23.1, you will see Allegro X Advanced Package Designer in the place of Allegro Package Designer +, as shown below: 

23.1 product title

Have you heard that starting SPB 23.1, Allegro Package Designer Plus (APD+) will be renamed as Allegro X Advanced Package Designer (Allegro X APD)? 

Allegro X APD offers multiple new features and enhancements on topics like Via Structures, Wirebond, Etchback, Text Wizards, 3D Canvas, and more. 

This post presents the new 3DX Canvas introduced in SPB 23.1. This can be invoked from Allegro X APD (from the menu item View > 3DX Canvas). 

Some of the key benefits of the new canvas: 

• This canvas addresses the scale and complexity in large modern package designs. It provides highly efficient visual representation and implementation of packages. 
  
• The new architecture enables high-performance 3D incremental updates by utilizing GPU for fast rendering. 
  
  
• Real-time 3D incremental updates are supported, which means that the 3D view is in sync with all changes to the database. 
  
  
• The new canvas provides 3D visualization support for packaging objects such as wire bonds, ball, die bump/pillar geometries, die stacks, etch back, and plating bar. 
  
  
• This release also introduces the interactive measurement tool for a 3D view of packages. Once you open 3DX Canvas, press the Alt key and you can select the objects you want to measure. 
  
• 3DX Canvas provides new 3D DRC Bond Wire Clearances with Real 3D DRC Checks. True 3D DRC in Constraint Manager has been introduced. If you open Constraint Manager, there will be a new worksheet added. Following DRC checks are supported: 

  Wire to Wire 
  Wire to Finger 
  Wire to Shape 
  Wire to Cline 
  Wire to Component

Power and Ground rings are exposed rings of metal surrounding a die that supply power/ground to the die and create a low-impedance path for the current flow. These rings ensure stable power distribution and reduce noise. Allegro X Package Designer Plus has a utility called Power/Ground Ring Generator which lets you define and place one or more shapes in the form of a ring around a die.

 To run the PWR/GND Generator Wizard, go to Route > Power/Ground Ring Generator or type "pring wizard" in the APD command window to invoke the Wizard.

This Wizard lets you define and place one or more shapes in the form of a ring around a die. The Power/Ground Ring Wizard creates up to 12 rings (shapes) at a time. If you require more rings, you can run the Power/Ground Ring Wizard as many times as needed. This command displays a wizard in which you can specify:

• The number of rings to be generated
• The creation of the first ring as a die flag (Die flag is the boundary of the die like the power ring.)
  • If you create a die flag and the first ring is the same net as the flag, you can enter a negative distance to overlap the ring and the die flag.
• Multiple options for placement of the rings with respect to:
  • Origination point
  • Distance from the edge of the die
  • Distance from the nearest die pin on each die side
• The reference designator of the die with which the rings will be used
• The distance between rings
• The width of each ring
• The corner types on each ring (arc, chamfer, and right-angle)
• An assigned net name for each ring
• A label for each ring

The rings are basic in nature. For other shape geometries or split rings, choose Shape > Polygon or Shape > Compose/Decompose Shape from the menu in the design window.

Depending on the options selected, the Power/Ground Ring Wizard UI changes, representing how the rings will be created. Verify the Wizard settings to ensure that the rings are created as intended.

1. When the Power/Ground Ring Wizard appears, set the number of rings to 2, accept the other defaults, and click Next. You can set Create first ring as die flag to create a basic die flag.

         2. Define Ring 1 and the net associated with it.

              a) Browse and choose Vss in the Net Names dialog box.

            b) Click OK.

            c) Specify the label as VSS.

            d) Click Next.

             The first ring should appear in your design. It is associated with the proper net; in this case, VSS.

2. For the second ring, choose the net as Vdd and specify the label as VDD.
3. Click Next.
4. Click Finish in the Result Verification screen to complete the process.

The completed rings appear as shown below.

Now, when you click on Power and Ground Die Pin and add wirebonds, you will see that the wirebonds are placed directly on the Power and Ground rings.

When things go wrong with your package design flow, it can sometimes be difficult to understand the cause of the issue. This can be something like a die component is wrongly identified as a BGA, a via stack has an alignment issue, or there are duplicate bondwires. These are just a few examples of issues; there can be many more. When interactive messages and log files do not help determine the problem, the Package Design Integrity Check tool becomes very handy. This feature lets you run integrity checks, which ensures that the database is configured correctly. 

To invoke the command from Allegro X Advanced Package Designer, use the Tools > Package Design Integrity menu. 

Or type package integrity at the Command  prompt. 

The Package Design Integrity Checks dialog box includes all categories and checks currently registered for the currently running product. You can enable all these categories and checks or only the one that you want to run. This utility can fix errors automatically (where possible). Errors and warnings are written to the “package_design_check.log” file.  

The utility can also be extended with your own custom rules based on your specific flows and needs. 

In SoC development, the verification cycle is a crucial phase that ensures products meet their specifications and function correctly. However, the complexity of modern SoC projects, with their constant data flow, multiple validation teams working in parallel, and tight schedules, presents significant challenges. This article explores these challenges and introduces Verisium Manager as a solution that embodies the 'One Tool Fits All' concept. This means that Verisium Manager is designed to handle all aspects of the verification process for SoC development, from planning to coverage analysis to regression testing, thereby addressing the complex needs of SoC verification.

The Hurdles in Traditional Validation Cycles

 A typical validation process involves planning, coverage analysis, and regression testing. This complexity is compounded by using separate tools for each activity, leading to multiple control environments, APIs, and databases, not to mention the array of tool owners. Such fragmentation results in constant data transfer and translation between systems, from the planning tool to the coverage analysis tool and then to the regression testing tool. This continuous movement of data causes delays, system instability, poor user experiences, and, ultimately, a dip in the quality of the validation process.

The use of multiple platforms leads to inefficiency and reduced productivity. What's needed is a unified system that can streamline the workflow, simplify the verification process, and enhance its effectiveness.

Envisioning the Ideal Solution: Verisium Manager

 The cornerstone of an efficient validation cycle is integration and simplicity. The ideal solution is a singular platform that consolidates planning, coverage analysis, and regression management into one smooth, unified process. Verisium Manager emerges as this much-needed solution, encompassing all the functionalities necessary to streamline the validation process. Its comprehensive nature instills confidence in its ability to handle all aspects of the verification cycle. It can be fully customized to address and enforce any validation methodology and can facilitate smooth integration into any customer environment.

Features that stand out in Verisium Manager include: 

• Unified Workflow: It acts as a single cockpit from which all activities are orchestrated, ensuring the validation teams' work is uninterrupted and seamlessly integrated.
• Customization and Integration: Verisium Manager supports customizing test-plan structures and mapping results per project, ensuring a perfect fit for various project requirements. Its ability to smoothly integrate into the project's environment and compute platforms is unparalleled.
• Support for Continuous Updates and Migration: The tool accommodates constant updates to project data and supports the migration of legacy data, ensuring that no historical data is lost in the transition to a new system.

Addressing Project-Specific Needs

 Verisium Manager recognizes diversity in different projects and offers project-specific solutions, including:

 Enforcing Project Test-Plan Structures and Attributes: It supports and enforces each project's unique test-plan structure and mapping guidelines.

• Unified Data Views and Measurements: Verisium Manager promotes a unified view of data across all teams and enforces unified measurements, ensuring consistency and clarity in the validation process.
• Enabling Project-Specific Actions and Integrations: The tool is designed to support project-specific actions directly from its graphical user interface and allows for smooth integration with in-house databases, dashboards, and the project execution stack.

Verisium Manager is the epitome of efficiency in software/hardware validation. Its differentiating features, such as support for customization, unified data view, and comprehensive coverage and regression requirements, make it an indispensable tool for any validation team looking to elevate their workflow.

PHY Interface for the PCI Express (PCIe), SATA, USB, DisplayPort, and USB4 Architectures (PIPE) enables the development of the Physical Layer (PHY) and Media Access Layer (MAC) design separately, providing a standard communication interface between these two components in the system.

In recent years, the PIPE interface specification has incorporated many enhancements to support new features and advancements happening in the supported protocols. As the supported features increase, so does the count of signals on PIPE interface. To address the issue of increasing signal count, the message bus interface was introduced in PIPE 4.4 and utilized for PCIe lane margining at the receiver and elastic buffer depth control.

In PIPE 5.0, all the legacy PIPE signals without critical timing requirements were mapped into message bus registers so that their associated functionality could be accessed via the message bus interface instead of implementing dedicated signals. It was decided that any new feature added in the new version of PIPE specification will be available only via message bus accesses unless they have critical timing requirements that need dedicated signals.

Message Bus Interface

The message bus interface provides a way to initiate and participate in non-latency-sensitive PIPE operations using a small number of wires. It also enables future PIPE operations to be added without adding additional wires. The use of this interface requires the device to be in a power state with PCLK running.

Control and status bits used for PIPE operations are mapped into 8-bit registers that are hosted in 12-bit address spaces in the PHY and the MAC. The registers are accessed using read-and-write commands driven over the signals M2P_MessageBus[7:0] and P2M_MessageBus[7:0]. These signals are synchronous with the PCLK and are reset with Reset#.

Message Bus Interface Commands

The 4-bit commands are used for accessing the PIPE registers across the message bus. A transaction consists of a command and any associated address and data.

All the following are time multiplexed over the bus from MAC and PHY:

1. Commands (write_uncommitted, write_committed, read, read completion, write_ack)
2. 12-bit address used for all types and read and writes
3. 8-bit data, either read or written

There can be cases where multiple PIPE interface signals can change on the same PCLK. To address such cases, the concept of write_uncommitted and write_committed is introduced.

The uncommitted write should be saved into a write buffer, and its associated data values are updated into the relevant PIPE register at a future time when a write_committed is received, taking effect during the same PCLK cycle. Once a write_committed is sent, no new writes, whether committed or uncommitted, and any read command may be sent until a write_ack is received. Also, it is allowed to send NOP commands between write uncommitted and write committed. 

A simple timing demonstration of message bus:

Message Address Space

MAC and PHY each implement unique 12-bit address spaces. These address spaces will host registers associated with the PIPE operations. MAC accesses PHY registers using M2P_MessageBus[7:0], and PHY accesses the MAC registers using the M2P_MessageBus[7:0].

The MAC and PHY access specific bits in the registers to: initiate operations, Initiate handshakes, and Indicate status.

Each 12-bit address space is divided into four main regions: the receiver address region, the transmitter address region, the common address region, and the vendor-specific address region.

Each register field has an attribute description of either level or 1-cycle assertion. When a level field is written, the value written is maintained by the hardware until the next write to that field or until a reset occurs. When a 1-cycle field is written to assert the value high, the hardware maintains the assertion for only a single cycle and then automatically resets the value to zero on the next cycle.

Cadence has a mature Verification IP solution for the verification of various aspects and topologies of PIPE PHY design. For more details, you may refer to the Simulation VIP for PIPE PHY | Cadence page, or you may send an email to support@cadence.com.

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.

Is there a way to generate coverage reports, not in ucd or any other format. I have written basic covergroup and passed arguments[-covoverwrite -cov_cgsample -cov_debuglog -coverage u] to the xrun command, however I don't see anything in sim directory, nor do I see anything in the logs indicating the covergroups have been hit. How can I confirm that cover groups are getting hit and essentially observe the bins. In Questa sim, you essentially get them as part of the log itself.

Have you ever wanted to write a DRC rule deck to check for space or width constraints on polygons? Or have you wondered how the multiple lines of an LVS rule deck extract and conduct a comparison between the schematic and layout? Maybe you've been curious about the role of rule deck writers in creating high-quality designs ready for tape-out.

If any of these questions interest you, there is good news: the latest version (v23.1) of the Physical Verification Rules Writer (PVLRW) course is designed to teach you rule deck writing. This free 16-hour online course includes audio and labs designed to make your learning experience comfortable and flexible. Whether you are new to the concept or an experienced CAD/PDK engineer, the course is structured to enhance your rule deck writing skills.

The PVLRW course covers six core modules: Layer Processing, DRC Rules, Layout Extraction, ERC and LVS Rules, Schematic Netlisting, and Coloring Rules. There are also three optional appendix sections. Each module explains relevant rules with syntax, concepts, graphics, examples, and case studies.

This course is based on tool versions PEGASUS231 and Virtuoso Studio IC231.

Pegasus Input and Output

Pegasus is a cloud-ready physical verification signoff solution that enables engineers to support faster delivery of advanced-node integrated circuits (ICs) to market.

Pegasus requires input data in the form of layout geometry, schematic netlists, and rules that direct the tool operation. The rules fall into two categories: those that describe the fabrication process and those that control the job-specific operation.

Pegasus provides log and report files, netlists, databases, and error databases as output.

Overview of Pegasus Rule File

The rule decks written in Physical Verification Language (PVL) work for the Cadence PV signoff tools Pegasus and PVS (Physical Verification System).   

The PVL rules are placed in a file that gets selected in a run from the GUI or the command line, as the user directs. PVL rules may be on separate lines within the file and can also be contained in named rule blocks.

Each line of code starts with a PVL rule that uses prefix type notation. It consists of a keyword followed by options, input layer or variable names, and output layer or variable names.

A rule block has the format of the keyword rule, followed by a rule name you wish to give it, followed by an opening curly brace. You enter the rules you wish to perform, followed by a closing curly brace on the last separate line.

  Sample Rule deck with individual lines of code and rule blocks.

DRC Rules

The first step in a typical Pegasus flow is a Design Rule Check (DRC), which verifies that layout geometries conform to the minimum width, spacing, and other fabrication process rules required by an IC foundry. Each foundry specifies its own process-dependent rules that must be met by the layout design.

There are three types of DRC rules: layer definition rules, layer derivation rules, and DRC design check rules. Layer definition rules identify the layers contained in the input layout database, and layer derivation rules derive additional layers from the original input layers, allowing the tool to test the design against specific foundry requirements using the design check rules.

A sample DRC Rule deck

A layout view displaying the DRC violations

LVS Rules

The Pegasus Layout Versus Schematic (LVS) tool compares the layout netlist with the schematic netlist to check for discrepancies.

There are two essential LVS rule sets: LVS extraction rules and comparison rules. LVS extraction rules help extract drawn devices and connectivity information from the input layout geometry data and outputs into a layout netlist. The LVS extraction rule set also includes the layer definition, derivation, extraction, connectivity, and net listing rules.

LVS comparison rules are associated with comparing the extracted layout netlist to a schematic netlist.

A sample LVS Rule deck. 

TCL, Macros, and Conditional commands

Tcl is supported and used in various Pegasus functionalities, such as Pegasus rule files and Pegasus configurator. Macros are functional templates that are defined once and can be used multiple times in a rule file. Conditional Commands are used to process or skip specific commands in the rule file.

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• On the Cadence Support portal, select Register Now and provide the requested information on the Registration page.
• You will need an email address and host ID to sign up.
• If you need help with registration, contact support@cadence.com.

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If you have questions about courses, schedules, online, public, or live onsite training, reach out to us at Cadence Training.

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Related Resources

About Knowledge Booster Training Bytes

Knowledge Booster Training Bytes is an online journal that relays information about Cadence Training videos, online courses, and upcoming webinars in the Learning section of the Cadence Learning and Support portal. This blog category brings you direct links to these videos, courses, and other related material on a regular basis. Subscribe to receive email notifications about our latest Custom IC Design blog posts.

1， Some components in the installation package cannot choose to install; even if they do not choose them, they will still be installed; just less shortcut icons, the documents are still released to the installation directory.

2， "Catia Application Frame" repeat the problem?
       “x:CadenceSPB_17.4 oolsin“
       ”x:CadenceSPB_17.4 oolsspatial“
       "Catia Application Frame" shouldn't you use the latest version?

3，Follow-up update patch cleaning the useless files and extra empty folder action !!!

The SPB17.4 installation package is currently the worst installation package I have seen for large-scale software packaging.

Hi,

reading Verilog®-A Language Reference I found this description of ddt function I don't understand:

Use the time derivative operator to calculate the time derivative of an argument.

ddt( input [ , abstol | nature ] )

input is a dynamic expression.

abstol is a constant specifying the absolute tolerance that applies to the output of the ddt operator. Set abstol at the largest signal level that you consider negligible.

nature is a nature from which the absolute tolerance is to be derived.

Can anyone explain how abstol and nature are defined? how using them? an example would be really appreciated.

Thanks

Andrea

I exported vplan to .odf file in vManager and after editing it I imported it to vManager. The vplan was expected to be synchronized and updated. However, nothing has changed to it. Does anyone know why?

I would like to send an update about a vmanager regression status x days after the regression has been run. In the current environment, the vmanager regression is creating a new filepath for logs automatically based on regression name/date, so I can't use a cron job to gather logs, as the log location is not known. 

I tried to use the pre session script to launch a detached shell script that would run after a delay, but when the pre_script runs, it waits until everything is completed before finishing and moving on to starting the regression.

Here is the test pre_script I am using:

#!/bin/sh

echo "pre_script start"

delay_script "FIRST" 1
nohup delay_script "SECOND" 30 & disown
delay_script "THIRD" 1

echo "pre_script end"
exit 0

Here is the test delay_script I am using:

#!/bin/sh

echo "Starting $1"

sleep $2

echo "Ending $1"

Here is the script output when run from terminal. After the "pre_script end", I get control back.

Here is the script output when run from vmanager. There is no "nohup", and the pre_session phase doesn't complete until all the delay scripts complete.

My question is, is there a better way to achieve my goal here? (The goal being to run a script from the vmanager log directory automatically x days after the regression). I think I could use the pre_script to send directory information for an auxiliary cron job to pick up, but I would prefer to not have to have extra cronjobs needed for this.

When analyzing multiple sessions simultaneously Verisium Manager crashed and reported below error messages:

# A fatal error has been detected by the Java Runtime Environment:
#
#  SIGSEGV (0xb) at pc=0x00007efc52861b74, pid=14182, tid=18380
#
# JRE version: OpenJDK Runtime Environment Temurin-17.0.3+7 (17.0.3+7) (build 17.0.3+7)
# Java VM: OpenJDK 64-Bit Server VM Temurin-17.0.3+7 (17.0.3+7, mixed mode, sharing, tiered, compressed oops, compressed class ptrs, g1 gc, linux-amd64)
# Problematic frame:
# C  [libucis.so+0x238b74]

......

For more details please refer to the attached log file "hs_err_pid21143.log".

Two approaches were tried to solve this problem but neither has worked.
Method.1:

Setting larger heap size of Java process by "-memlimit" options.For example "vmanager -memlimit 8G".

Method.2:

Enlarging stack memory size limit of the Coverage engine by setting "IMC_NATIVE_STACKSIZE" environment variable to a larger value. For example "setenv IMC_NATIVE_STACKSIZE 1024000"

According to "hs_err_pid*.log" it is almost certain that the memory overflow triggered Java's CrashOnOutOfMemoryError and caused Verisium Manager to crash. There are some arguments about memory management of Java like "Xms, Xmx, ThreadStackSize, Xss5048k etc" and maybe this problem can be fixed by setting these arguments during analysis. However, how exactly does Verisium Manager specify these arguments during analysis? I tried to set them by the form of setting environment variables before analysis but it didn't work in analysis and their values didn't change.

Is there something wrong with my operation or is there a better solution?

Thank you very much.

I'm working on the code coverage. Doing a metrics analysis by default we see overall average grade and overall covered. But when i do a block analysis on an instance i see overall covered grade, code covered grade, block covered grade, statement covered grade, expression covered grade, toggle covered grade.

As I dont know the difference I started to read the IMC user guide and came to know there are 3 things we come across while doing a code coverage local, covered, average

From my understanding

local - child instances metrics doesnt reach the parent level. For example, we have an instance Q and its sub instances like Q.a, Q.b. Block Local grade of Q can be 100% even when its instances Q.a and Q.b a block local grades isnt at 100%.

In the attached image there is formula 

The key difference between average and covered is the weights.

Average : Mathematically taking the above scenario where Q.a, and Q.b has 10 blocks each. Q.a has covered 8 blocks and q.b has covered 2 blocks. Now if we take the normal average it should be total covered/ totatl number = 8+2/10+10 yielding 50%. But when we add weights saying Q.a is 70% and Q.b is 30% the new number would be (8*0.7+2*0.3) / (10*0.7+10*0.3) resulting 62%. Because of the weights we see 12% bump.

Covered: there is no role of weights.

Among these 3 metrics i've changed my default view to this in the image to get more realistic picture when i do analyze metrics. Do you guys agree with the approach?

I'm currently work in coverage analysis. In my design certain register bits remain unused, which could potentially lower toggle coverage. Specifically, I'd like to know how to disable coverage for specific unused register bits within a 32-bit register. For instance, I want to deactivate coverage for bit 17 and bit 20 in a 32-bit register to optimize toggle coverage. Could you please provide guidance on how to accomplish this?

Hello,

I have a question about toggle coverage.

In my case, there are many unused registers or wires that are affecting the toggle coverage score negatively.

Is it possible to automatically exclude registers or wires that are not used from toggle coverage?

My RTL code is as follows, Is it possible to automatically disable tb.top1.b and tb.top1.c without using an exclude file?

module top1;

  reg a;

  reg b;

  reg [31:0] c;

  initial

  begin

  #1 a=1'b0;

  #1 a=1'b1;

  #1 a=1'b0;

  end

endmodule

module tb;

  top1 top1();

endmodule

Hi, I'm using the xcelium simulator to simulate a testbench, in which I first stimulate my design to do something (part "A") and then do a direct follow-up test on the design (part "B").

I need two things from this testbench: the results of the test (part "B", passed/failed) and coverage information, but the coverage information should only include part A and explicitly not part B.

I could do the following: run the testbench with part A and B, get the "passed/failed" result of the test and then follow up another simulator run with another testbench, that only includes part A and get the coverage information from that simulation run.

Is there a way to force xcelium to give me the coverage information of only a part of the simulation? Ideally, I would like to write the verilog code of my testbench to look something like this:

• do A
• dump coverage information
• do B

But maybe there is another way to tell xcelium to consider only part of the testbench for the coverage information. I did have a look at the manual, but was not able to find something useful for this problem. Any ideas?

Hi, 

I am running a regression in order to collect the coverage. However I have an issue. I am setting a signal to 0 when reset is de-asserted  then this signal takes a fixed value when the reset is asserted. 

if(!rst_n) 
init_val= 'b0;

else 

init_val= 31'h34013FF7

the issue is that I got 0%  coverage for the init_value since we only have a rising edge and the signal is not toggling during the simulation. is there an option to collect coverage when there is a rising edge or a falling edge? 

I have been using the rank feature to identify tests that are redundant in our environment, but then I realized I'd also like to be able to see exactly what coverage goes into increasing the delta_cov value for a given test. If I had a test in my rank report that contributed 0.5% of the delta_cov, how could I got about seeing exactly where that 0.5% was coming from? It seems like that might be part of the correlate function, but I couldn't mange to find a way to see what specific coverage was being contributed for a given test.

Attached is the latest revision of the venerable Specman-Matlab package (Lead Application Engineer Jangook Lee is the latest to have refreshed it for a customer in Asia to support 64 bit mode.  Look for a guest blog post from him on this package shortly.)

There is a README file inside the package that gives a detailed overview, shows how to run a demo and/or validate it’s installed correctly, and explains the general test flow.  The test file included in the package called "test_get_cmp_mdim.e" shows all the capabilities of the package, including:

* Using Specman to initialize and tear down the Matlab engine in batch mode

* Issuing Matlab commands from e-code, using the Specman command prompt to load .m files, initializing variables, and other operational tasks.

* Transfering data to and from the Matlab engine to Specman / an e language test bench

* Comparing data of previously retrieved Matlab arrays

* Accessing Matlab arrays from e-code without converting them to e list data structure

* Convert Matlab arrays into e-lists

Happy coding!

Team Specman

Che(read more)

Hi

I have fixed a SPACING RULE (SP1) for a CLASS_DIFF_PAIR whereas for via associated to the net (DP_VIA), the DISTANCE > 60mils respect to ANY other vias (PTH, BB, TEST vias)

Now my problem is that this rules should NOT be applied for GND VIAS (STICHING VIA) which must be placed at a distance < 40mils respect to DP_VIA

How to create an exemption to the SPACING RULE (SP1)?

I am using OrCAD PCB Designer Standard version 17.4-2019. I want to force update the Package_Height_Max property on the place bound top shape. The footprint library that we've created has that property set in the dra file, but I'd like to override that from capture so I can be certain that the height is correct.

This is coming from a place where we have created a very large footprint library over that past ++ years. Everyone who creates a new footprint is supposed to make sure that we add Package_Height_Max to the footprint, but of course footprints get reused for various parts, not all of which will have the same package height. What I want to do is export a list of package heights from our part database and then import the package heights into Capture and override the package height in the footprint.

I have found a post here  Using Height Property from Orcad Capture which says its not possible, but it also says its from 15 years ago, so maybe things have changed?

Loading new netlist into 23.1 Apparently it does not like many of the specified footprints or padstacks. I have to open the footprint in 231., save the pad stack then save the footprint. This is very time consuming and frustrating to say the least.

I also get the following message

WARNING(SPMHNI-194): Symbol 'SMD_SOD123_ANODE_PIN1' used by RefDes D30 for device 'DIODE_0_SMD_SOD123_ANODE_PIN1_1N4148W-7-F' not found.

The symbol either does not exist in the library path (PSMPATH) or is an old symbol from a previous release.  

Set the correct library path if not set or use dbdo

     The current version of software is unable to open design smd_sod123_anode_pin1.

The design was last saved using version 16.5 and must be updated using DB Doctor. [help]


Going to DB Doctor does nothing, no option to update a footprint?

Tom

Power efficiency is a critical factor in the fast-evolving world of semiconductor design.

The IEEE 1801 standard, also known as UPF (Unified Power Format), was developed by the IEEE to address the intricate challenges associated with power management in contemporary semiconductor designs. This standard offers a uniform framework for defining power domains, power states, and power intent, ensuring consistency across diverse tools and phases of the design process. By utilizing UPF, you can precisely model and regulate power consumption, a critical aspect for battery-operated devices, high-performance computing, and energy-efficient designs.

The key concepts of IEEE 1801 are:

1. Power domains
2. Power states
3. Power gating and isolation
4. Power switches
5. Level shifters, isolation, and retention cells
6. Macro model

Based on these building blocks, you write the power intent of the design.

The power intent for the design includes identifying/implementing low-power strategies that provide a clear description of the power architecture of a design.

The power definitions can effectively manage power consumption and ensure the chip meets its power and performance requirements.

You can start by creating the Power Supply Network, which defines how power is supplied to the design's various power domains and logic cells.

What's the next step to build the file? How do you understand the various concepts related to IEEE 1801? How do you complete the rest of the power intent file?

Relax!

Gear up to attend the training class created just for you to dive deep into the entire format and explore this exciting power specification method/format with hands-on labs in one day!

Training

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This course is a complete tutorial for understanding the fundamentals of IEEE 1801 low-power specification format concepts. You learn about IEEE 1801 power supply networks, ground ports and nets, creating and connecting supply ports/nets, power domain, power switch, power states, defining isolation and level shifter strategies, hierarchical IEEE 1801, and various versions of the IEEE 1801. You also explore how power intent information can be used for a design across various flow stages, such as functional verification, synthesis, logic equivalency checking, place-and-route, test, timing signoff, power integrity, and so forth, using Cadence^® tools.

Labs

We ensure that your learning journey is smooth with hands-on labs covering various design scenarios.

Lab Videos

Now, the exciting part is that to help you further, we have created engaging videos of the training labs. You can refer to the lab module's instructions in demo format at https://support.cadence.com.

Lab Demo: Checking Power Supply Network in IEEE 1801 format and Running IEEE 1801 Quality Checks using Conformal Low Power

Lab Demo: Checking Power Intent for The Macro Connections in IEEE 1801 Format And Running IEEE 1801 Quality Checks using Conformal Low Power 

Online Class

Here is the course link.

Get ready for the most thrilling experience with Accelerated Learning!

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Take the quiz and increase your learning pace!!

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Grab your Badge after finishing the training and flaunt the expertise you have built up. 😊

Ready to take a tour of this power specification world? Let's help you enroll in this course.

We organize this training for you as a "Blended" or "Live" training. Please reach out to Cadence Training for further information. If you want to ensure you are always the first to know about anything new in training, you can use the SUBSCRIBE button on the landing page to sign up for our regular training newsletters.

Related Short Training Bytes/Videos

Enhance the learning experience with short videos:

Genus Synthesis Solution: Video Library

 Joules RTL Power Solution: Video Library

Related Training

 Low-Power Synthesis Flow with Genus Synthesis Solution

Genus Low-Power Synthesis Flow with IEEE 1801

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In an era of abundant and constantly evolving information, the challenge is not just accessing knowledge but understanding and applying it effectively. AI is a transformative technology that is reshaping how we learn, work, and grow. In this blog, we’ll explore how AI accelerates our knowledge acquisition and understand how it can relate to the process of learning, which connects with our daily lives.

The role of AI is to accelerate knowledge by personalizing learning experiences, providing instant access to information, and offering data-driven insights. AI empowers us to learn more efficiently and effectively in many ways. I won't go into much detail, as we are already busy searching for the meaning of AI and what it can do; however, I want to share one inspiring fact about AI. It can analyze vast amounts of data in seconds, making sense of complex information and providing instantaneous actionable insights or concise answers. I understand that humans are looking to speed up things, which can help us understand technology better and perform our tasks faster.

The main reason AI is in focus is because of its ability to perform tasks faster than ever. We aim to enhance the performance of all our products, including the everyday household electronic items we use. Similarly, are we striving to accelerate the learning process? I am committed to assisting you, and one such method is concise, short (minute-long) videos.

In today's fast-paced world, where attention spans are shorter than ever, the rise of social media platforms has made it easier for anyone to create and share short videos. This is where minute videos come in. These bite-sized clips offer a quick and engaging way to deliver information to the audience with a significant impact. Understanding the definitions of technical terms in VLSI Design can often be accomplished in just a minute.

Below are the definitions of the essential stages in the RTL2GDSII Flow. For further reference, these definitions are also accessible on YouTube.

Want to Learn More?

The Cadence RTL-to-GDSII Flow training is available as both "Blended" and "Live" Please reach out to Cadence Training for further information.

And don't forget to obtain your Digital Badge after completing the training!

• You can check out a free Online Version of the training above, which is available 24/7 for all customers with a Cadence Learning ans Support Portal
• You will also have access to our Training Byte Library then which is full of hundres of troubleshooting videos, like the following: What is Digital Implementation?
• You can find more instructions how to get the best out of the Portal in this blog.
• If you would like to stay up-to-date with the latest news and information about Cadence trainings and webinars, subscribe to the Cadence Training emails.

Related Blogs

Training Insights – Why Is RTL Translated into Gate-Level Netlist?

Did You Miss the RTL-to-GDSII Webinar? No Worries, the Recording Is Available!

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