Typically, analog designers verify their AMS IP in schematic driven, interactive environment, while SoC designers use a UVM SystemVerilog testbench ran from a command line. In our last MS blog, we talked about automation for reusing SystemVerilog testbench by analog designers in order to verify AMS IP in exactly same context as in its SoC integration, hence reducing surprises and unnecessary iterations.

But, what about other direction: selecting proper AMS IP views for SoC Verification? Manually export netlist from Virtuoso and then manually assemble together all of the files for use with in command line driven flow? Often, there are multiple views for the same instance (RNM, analog behavioral model, transistor netlist). Which one to pick? Who is supposed to update configuration files? We often work concurrently and update the AMS IP views frequently. Obviously, manually selecting correct and most up-to-date AMS IP views for SoC Verification is tedious and error prone. Thanks to Cadence Innovation, there is a better way!

Cadence has developed a Command-Line IP Selector (CLIPS) product as part of the Virtuoso^® environment, which:

• Bridges the gap between MS SoC command-line setup and the Virtuoso-based analog mixed-signal configuration
• Allows seamless importing of AMS IP from the Virtuoso environment into an existing digital verification setup
• Provides a GUI-based and command-line use model, flexible to fit into an existing design flow methodologyCLIPS reads MS SoC command (irun) files, identifies required AMS IP modules, uses Virtuoso ADE setup files to properly netlist required modules, and pulls the AMS IP out of the Virtuoso environment. All necessary files are properly extracted/prepared and package as required for the MS SoC command line verification run. CLIPS setup can be saved and rerun as a batch process to ensure the latest IP from the hierarchy is being simulated.

For more details, please see CLIPS Rapid Adoption Kit at Cadence Online Support page

Verification is the top challenge in mixed-signal design. Bringing analog and digital domains together into unified verification planning, simulating, and debugging is a challenging task for rapidly increasing size and complexity of mixed-signal designs. To more completely verify functionality and performance of a mixed-signal SoC and its AMS IP blocks used to build it, verification teams use simulations at transistor, analog behavioral and real-number model (RNM) and RTL levels, and combination of these.

In recent years, RNM and simulation is being adopted for functional verification by many, due to advantages it offers including simpler modeling requirements and much faster simulation speed (compared to a traditional analog behavioral models like Verilog-A or VHDL-AMS). Verilog-AMS with its wreal continue to be popular choice. Standardization of real number extensions in SystemVerilog (SV) made SV-RNM an even more attractive choice for MS SoC verification.

Verilog-AMS/wreal is scalar real type. SV-RNM offers a powerful ability to define complex data types, providing a user-defined structure (record) to describe the net value. In a typical design, most analog nodes can be modeled using a single value for passing a voltage (or current) from one module to another. The ability to pass multiple values over a net can be very powerful when, for example, the impedance load impact on an analog signal needs to be modeled. Here is an example of a user-defined net (UDN) structure that holds voltage, current, and resistance values:

When there are multiple drives on a single net, the simulator will need a resolution function to determine the final net value. When the net is just defined as a single real value, common resolution functions such as min, max, average, and sum are built into the simulator.  But definition of more complex structures for the net also requires the user to provide appropriate resolution functions for them. Here is an example of a net with three drivers modeled using the above defined structural elements (a voltage source with series resistance, a resistive load, and a current source):

To properly solve for the resulting output voltage, the resolution function for this net needs to perform Norton conversion of the elements, sum their currents and conductances, and then calculate the resolved output voltage as the sum of currents divided by sum of conductances.

With some basic understanding of circuit theory, engineers can use SV-RNM UDN capability to model electrical behavior of many different circuits. While it is primarily defined to describe source/load impedance interactions, its use can be extended to include systems including capacitors, switching circuits, RC interconnect, charge pumps, power regulators, and others. Although this approach extends the scope of functional verification, it is not a replacement for transistor-level simulation when accuracy, performance verification, or silicon correlation are required:  It simply provides an efficient solution for discretely modeling small analog networks (one to several nodes).  Mixed-signal simulation with an analog solver is still the best solution when large nonlinear networks must be evaluated.

Cadence provides a tutorial on EEnet usage as well as the package (EEnet.pkg) with UDN definitions and resolution functions and modeling examples. To learn more, please login to your Cadence account to access the tutorial.

Analog and Mixed-signal (AMS) designs are increasingly using active power management to minimize power consumption. Typical mixed-signal design uses several power domains and operate in a dozen or more power modes including multiple functional, standby and test modes. To save power, parts of design not active in a mode are shut down or may operate at reduced supply voltage when high performance is not required. These and other low power techniques are applied on both analog and digital parts of the design. Digital designers capture power intent in standard formats like Common Power Format (CPF), IEEE1801 (aka Unified Power Format or UPF) or Liberty and apply it top-down throughout design, verification and implementation flows. Analog parts are often designed bottom-up in schematic without upfront defined power intent. Verifying that low power intent is implemented correctly in mixed-signal design is very challenging. If not discovered early, errors like wrongly connected power nets, missing level shifters or isolations cells can cause costly rework or even silicon re-spin. 

Mixed-signal designers rely on simulation for functional verification. Although still necessary for electrical and performance verification, running simulation on so many power modes is not an effective verification method to discover low power errors. It would be nice to augment simulation with formal low power verification but a specification of power intent for analog/mixed-signal blocs is missing. So how do we obtain it? Can we “extract” it from already built analog circuit? Fortunately, yes we can, and we will describe an automated way to do so!

Virtuoso Power Manager is new tool released in the Virtuoso IC6.1.8 platform which is capable of managing power intent in an Analog/MS design which is captured in Virtuoso Schematic Editor. In setup phase, the user identifies power and ground nets and registers special devices like level shifters and isolation cells. The user has the option to import power intent into IEEE1801 format, applicable for top level or any of the blocks in design. Virtuoso Power Manager uses this information to traverse the schematic and extract complete power intent for the entire design. In the final stage, Virtuoso Power Manager exports the power intent in IEEE1801 format as an input to the formal verification tool (Cadence Conformal-LP) for static verification of power intent.

Cadence and Infineon have been collaborating on the requirements and validation of the Virtuoso Power Manager tool and Low Power verification solution on real designs. A summary of collaboration results were presented at the DVCon conference in Munich, in October of 2018.  Please look for the paper in the conference proceedings for more details. Alternately, can view our Cadence webinar on Verifying Low-Power Intent in Mixed-Signal Design Using Formal Method for more information.

Introduction to AMSD Flex mode and its benefits.(read more)

This blog talks about how to enable the AMS Designer flex mode.(read more)

When the Arduino Mega2560 is added to the first serial port, the dynamic memory is 2000 bytes, and when the second serial serial is added, the dynamic memory is 4000 bytes. Now I need to add the third Serial serial port. The dynamic memory is 6000 bytes. Due to the many variables in the program itself, the dynamic memory is not enough. Please help me how to save the dynamic memory?

Cadence_SPB_17.4-2019 + Matlab R2019a

请参考本文档中的步骤进行操作

1，打开BJT_AMP.opj

2，设置Matlab路径

3，打开BJT_AMP_SLPS.slx

4，打开后，设置PSpiceBlock，出现或CEFSimpleUI.exe停止工作

5，添加模块

6，相同

7，打开pspsim.slx

8，相同

9，打开C： Cadence Cadence_SPB_17.4-2019 tools bin

orCEFSimpleUI.exe和orCEFSimple.exe

10，相同

我想问一下如何解决，非常感谢！

Hello,

I'm reading the Design specification for IP6514E.

We will use the DAC mode.

It would seem to be very simple but I don't see any code sequence, i.e.

  1.Write 03(Basic Read) to this register

  2, Write start adress to this register

  3. Write "execute" to this register

  4. Read the data from this register

Thanks,

Stefan

Bumps are central to the Virtuoso MultiTech Framework solution. Bumps provide a connection between stacked ICs, interposers, packages, and boards. Bump locations, connectivity, and other attributes are the basis for creating TILPs, which we combine to create system-level layouts.(read more)

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This blog discusses key features of concurrently editing a hierarchical cellview.(read more)

Hello everyone, today I’d like to talk to you about the recent enhancements to Die export in the Virtuoso RF Solution, most of which were released in ICADVM 18.1 ISR10. What’s the background for these enhancements? Exporting an abstract of a Die, which basically represents the outer boundary of the Die with I/O locations, as an intermediate file to exchange information between various Cadence tools (i.e., the Innovus, Virtuoso, and Allegro platforms) is not a new feature. This capability existed even prior to the Virtuoso RF Solution. However, the entire functionality was rewritten from scratch when we first started developing the Virtuoso RF Solution because the previous feature was deemed archaic, its performance and capacity needed to be enhanced, and use model needed to be modernized. This effort has been made in various phases, with the last round being completed and released in ICADVM18.1 ISR10.(read more)

The way you need blocks of different sizes and styles to build great Lego masterpieces, a complex WSP-based design requires stitching together routing regions with multiple patterns that follow different WSSPDef periods. Let's see how you can achieve this. (read more)