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Cadence Collaborates with Test & Verification Solutions on Portable Stimulus

The Cadence® Connections® Verification Program brings together a worldwide network of services, training, and IP development experts that support Cadence verification solutions. The program members help customer accelerate the adoption of new...(read more)




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Integration and Verification of PCIe Gen4 Root Complex IP into an Arm-Based Server SoC Application

Learn about the challenges and solutions for integrating and verification PCIe(r) Gen4 into an Arm-Based Server SoC. Listen to this relatively short webinar by Arm and Cadence, as they describe the collaboration and results, including methodology and...(read more)




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Willamette HDL and Cadence Develop the Industry's First PSS Training Course for Perspec System Verifier

Cadence continues to be a leader in SoC verification and has expanded our industry investment in Accellera portable stimulus language standardization. Some customers have expressed reservations that portable stimulus requires the effort of learn...(read more)




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Visibility to "component value" property in Edit/Properties dialog?

Hi, I want to add values to components in my SiP design such as 1nF or 15nH. There is already in existence a COMP_VALUE property reserved for this as shown during BOM generation. This property is not visible under the Edit/Properties dialog for component or symbol find filters. We have already created user properties called COMP_MFG and COMP_MFG_PN that it editable at a component level. When we try to add COMP_VALUE it is reported as a reserved name in Cadence but this name is not listed in the properties dialog. Is there a way to turn on the visibility and editablility of this or other hidden reserved Cadence property names? How can I assign a string value to the COMP_VALUE property?

Thanks




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How to check a cluster of same net vias spacing, with have no shape or cline covered

 

Hi all,

I have a question regarding the manufacture : how to check a cluster of same net vias spacing, with have no shape or cline covered




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IC Packagers: Shape Connectivity in the Allegro Data Model

Those who work in the IC Packaging design space have some unique challenges. We bridge between the IC design world (90/45-degree traces with rectangular and octagonal pins) and the PCB domain...

[[ Click on the title to access the full blog on the Cadence Community site. ]]




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1G Mobile: AMPS, TOPS, C-450, Radiocom 2000, and All Those Japanese Ones

You can't read anything about technology these days without reading about 5G. But before there was 5G, there was 4G. And before that 3G, 2G, and 1G. A 0G even. For the next few Thursdays,...

[[ Click on the title to access the full blog on the Cadence Community site. ]]




co

Specman’s Callback Coverage API

Our customers’ tests have become more complex, longer, and consume more resources than before. This increases the need to optimize the regression while not compromising on coverage. Some advanced...

[[ Click on the title to access the full blog on the Cadence Community site. ]]




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Linley Processor Conference 2020 Keynote

The Linley Processor Conference always opens with a keynote by Linley Gwenapp giving an overview of processors in whatever is the hottest area. Most of the other presentations during the conference...

[[ Click on the title to access the full blog on the Cadence Community site. ]]




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Wally Rhines: Predicting Semiconductor Business Trends After Moore's Law

I recently attended a webinar presented by Wally Rhines about his new book, Predicting Semiconductor Business Trends After Moore's Law . Wally was the CEO of Mentor, as you probably know. Now he...

[[ Click on the title to access the full blog on the Cadence Community site. ]]




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Computational Software: A New Paradigm for EDA Tools

Cadence has a new white paper out on Computational Software . I've written on these topics in Breakfast Bytes, most recently in the posts: Computational Software System Analysis: Computational...

[[ Click on the title to access the full blog on the Cadence Community site. ]]




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Tales from DAC: Semiconductor Design in MY Cloud? It's More Likely Than You Think

Everyone keeps talking about “the cloud” this and “the cloud” that these days—but you’re a semiconductor designer. Everyone keeps saying “the cloud” is revolutionizing all aspects of electronics design—but what does it mean for you? Cadence's own Tom Hackett discussed this in a presentation at the Cadence Theater during DAC 2019.

What people refer to as “the cloud” is commonly divided into three categories: Infrastructure as a Service (IaaS), Platform as a Service (PaaS), and software as a Service (SaaS). With IaaS, you bring your own software—i.e. loading your owned or appropriately licensed tools onto cloud hardware that you rent by the minute. This service is available from providers like Google Cloud Platform, Amazon Web Service, and Microsoft Azure. In PaaS (also available from the major cloud providers), you create your own offering using capabilities and a software design environment provided by the cloud vendor that makes subsequent scaling and distribution really easy because the service was “born in the cloud”.  Lastly, there’s SaaS, where the cloud is used to access and manage functionality and data without requiring users to set up or manage any of the underlying infrastructure used to provide it.  SaaS companies like Workday and Salesforce deliver their value in this manner.  The Cadence Cloud portfolio makes use of both IaaS and SaaS, depending on the customers’ interest.  Cadence doesn’t have PaaS offerings because our customers don’t create their own EDA software from building blocks that Cadence provides.

All of these designations are great, but you’re a semiconductor designer. Presumably you use Workday or some similar software, or have in the past when you were an intern, but what about all of your tools? Those aren’t on the cloud.

Wait—actually, they are.

Using EDA tools in the cloud allows you to address complexity and data explosion issues you would have to simply struggle through before. Since you don’t have to worry about having the compute-power on-site, you can use way more power than you could before. You may be wary about this new generation of cloud-based tools, but don’t worry: the old rules of cloud computing no longer apply. Cloud capacity is far larger than it used to be, and it’s more secure. Updates to scheduling software means that resource competition isn’t as big of a deal anymore. Clouds today have nearly unlimited capacity—they’re so large that you don’t ever need to worry about running out of space.

The vast increase in raw compute available to designers through the cloud makes something like automotive functional safety verification, previously an extremely long verification task, doable in a reasonable time frame. With the cloud, it’s easy to scale the amount of compute you’re using to fit your task—whether it’s an automotive functional safety-related design or a small one.

Nowadays, the Cadence Cloud Portfolio brings you the best and brightest in cloud technology. No matter what your use case is, the Cadence Cloud Portfolio has a solution that works for you. You can even access the Palladium Cloud, allowing you to try out the benefits of an accelerator without having to buy one.

Cloud computing is the future of EDA. See the future here.




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Specman: Analyze Your Coverage with Python

In the former blog about Python and Specman: Specman: Python Is here!, we described the technical information around Specman-Python integration. Since Python provides so many easy to use existing libraries in various fields, it is very tempting to leverage these cool Python apps.

Coverage has always been the center of the verification methodology, however in the last few years it gets even more focus as people develop advanced utilities, usually using Machine Learning aids. Anyhow, any attempt to leverage your coverage usually starts with some analysis of the behavior and trends of some typical tests. Visualizing the data makes it easier to understand, analyze, and communicate. Fortunately, Python has many Visualization libraries.

In this blog, we show an example of how you can use the plotting Python library (matplotlib) to easily display coverage information during a run. In this blog, we use the Specman Coverage API to extract coverage data, and a Python module to display coverage grades interactively during a single run and the way to connect both.

Before we look at the example, if you have read the former blog about Specman and Python and were concerned about the fact that python3 is not supported, we are glad to update that in Specman 19.09, Python3 is now supported (in addition to Python2).

The Testcase
Let’s say I have a stable verification environment and I want to make it more efficient. For example: I want to check whether I can make the tests shorter while hardly harming the coverage. I am not sure exactly how to attack this task, so a good place to start is to visually analyze the behavior of the coverage on some typical test I chose. The first thing we need to do is to extract the coverage information of the interesting entities. This can be done using the old Coverage API. 

Coverage API
Coverage API is a simple interface to extract coverage information at a certain point. It is implemented through a predefined struct type named user_cover_struct. To use it, you need to do the following:

  1. Define a child of user_cover_structusing like inheritance (my_cover_struct below).
  2. Extend its relevant methods (in our example we extend only the end_group() method) and access the relevant members (you can read about the other available methods and members in cdnshelp).
  3. Create an instance of the user_cover_structchild and call the predefined scan_cover() method whenever you want to query the data (even in every cycle). Calling this method will result in calling the methods you extended in step 2.  

 The code example below demonstrates these three steps. We chose to extend the end_group() method and we keep the group grade in some local variable. Note that we divide it by 100,000,000 to get a number between 0 to 1 since the grade in this API is an integer from 0 to 100,000,000. 

 struct my_cover_struct like user_cover_struct {
      !cur_group_grade:real;
   
      //Here we extend user_cover_struct methods
      end_group() is also {
      cur_group_grade = group_grade/100000000;        
      }
};
 
extend sys{
      !cover_info : my_cover_struct;
       run() is also {
          start monitor_cover ();
     };
     
     monitor_cover() @any is {
         cover_info = new;
         
         while(TRUE) {
             // wait some delay, for example –
             wait [10000] * cycles;
          
            // scan the packet.packet_cover cover group
            compute cover_info.scan_cover("packet.packet_cover");
          };//while
      };// monitor_cover
};//sys

Pass the Data to a Python Module
After we have extracted the group grade, we need to pass the grade along with the cycle and the coverage group name (assuming there are a few) to a Python module. We will take a look at the Python module itself later. For now, we will first take a look at how to pass the information from the e code to Python. Note that in addition to passing the grade at certain points (addVal method), we need an initialization method (init_plot) with the number of cycles, so that the X axis can be drawn at the beginning, and end_plot() to mark interesting points on the plot at the end. But to begin with, let’s have empty methods on the Python side and make sure we can just call them from the e code.

 # plot_i.py
def init_plot(numCycles):
    print (numCycles)
def addVal(groupName,cycle,grade):
    print (groupName,cycle,grade)
def end_plot():
    print ("end_plot") 

And add the calls from e code:

struct my_cover_struct like user_cover_struct {
     @import_python(module_name="plot_i", python_name="addVal")
     addVal(groupName:string, cycle:int,grade:real) is imported;
  
     !cur_group_grade:real;
  
     //Here we extend user_cover_struct methods
     end_group() is also {
         cur_group_grade = group_grade/100000000;
         
        //Pass the values to the Python module
         addVal(group_name,sys.time, cur_group_grade);      
     }   //end_group
};//user_cover_struct
 
extend sys{
     @import_python(module_name="plot_i", python_name="init_plot"
     init_plot(numCycles:int) is imported;
    
     @import_python(module_name="plot_i", python_name="end_plot")
     end_plot() is imported;
    
     !cover_info : my_cover_struct;
     run() is also {
         start scenario();
    };
    
    scenario() @any is {
         //initialize the plot in python
         init_plot(numCycles);
        
         while(sys.time<numCycles)
        {
             //Here you add your logic     
             
            //get the current coverage information for packet
            cover_info = new;
            var num_items:=  cover_info.scan_cover("packet.packet_cover");
           
            //Here you add your logic       
        
        };//while
        
        //Finish the plot in python
        end_plot();
   
    }//scenario
}//sys
 
  • The green lines define the methods as they are called from the e
  • The blue lines are pre-defined annotations that state that the method in the following line is imported from Python and define the Python module and the name of the method in it.
  • The red lines are the calls to the Python methods.

 Before running this, note that you need to ensure that Specman finds the Python include and lib directories, and Python finds our Python module. To do this, you need to define a few environment variables: SPECMAN_PYTHON_INCLUDE_DIR, SPECMAN_PYTHON_LIB_DIR, and PYTHONPATH. 

 The Python Module to Draw the Plot
After we extracted the coverage information and ensured that we can pass it to a Python module, we need to display this data in the Python module. There are many code examples out there for drawing a graph with Python, especially with matplotlib. You can either accumulate the data and draw a graph at the end of the run or draw a graph interactively during the run itself- which is very useful especially for long runs.

Below is a code that draws the coverage grade of multiple groups interactively during the run and at the end of the run it prints circles around the maximum point and adds some text to it. I am new to Python so there might be better or simpler ways to do so, but it does the work. The cool thing is that there are so many examples to rely on that you can produce this kind of code very fast.

# plot_i.py
import matplotlib
import matplotlib.pyplot as plt
plt.style.use('bmh')
#set interactive mode
plt.ion()
fig = plt.figure(1)
ax = fig.add_subplot(111)
# Holds a specific cover group
class CGroup:
    def __init__(self, name, cycle,grade ):
        self.name = name
        self.XCycles=[]
        self.XCycles.append(cycle)
        self.YGrades=[]
        self.YGrades.append(grade)  
        self.line_Object= ax.plot(self.XCycles, self.YGrades,label=name)[-1]             
        self.firstMaxCycle=cycle
        self.firstMaxGrade=grade
    def add(self,cycle,grade):
        self.XCycles.append(cycle)
        self.YGrades.append(grade)
        if grade>self.firstMaxGrade:
            self.firstMaxGrade=grade
            self.firstMaxCycle=cycle          
        self.line_Object.set_xdata(self.XCycles)
        self.line_Object.set_ydata(self.YGrades)
        plt.legend(shadow=True)
        fig.canvas.draw()
     
#Holds all the data of all cover groups   
class CData:
    groupsList=[]
    def add (self,groupName,cycle,grade):
        found=0
        for group in self.groupsList:
            if groupName in group.name:
                group.add(cycle,grade)
                found=1
                break
        if found==0:
            obj=CGroup(groupName,cycle,grade)
            self.groupsList.append(obj)
     
    def drawFirstMaxGrade(self):
        for group in self.groupsList:
            left, right = plt.xlim()
            x=group.firstMaxCycle
            y=group.firstMaxGrade
           
            #draw arrow
            #ax.annotate("first maximum grade", xy=(x,y),
            #xytext=(right-50, 0.4),arrowprops=dict(facecolor='blue', shrink=0.05),)
           
            #mark the points on the plot
            plt.scatter(group.firstMaxCycle, group.firstMaxGrade,color=group.line_Object.get_color())
          
            #Add text next to the point   
            text='cycle:'+str(x)+' grade:'+str(y)   
            plt.text(x+3, y-0.1, text, fontsize=9,  bbox=dict(boxstyle='round4',color=group.line_Object.get_color()))                                                                      
       
#Global data
myData=CData()
 
#Initialize the plot, should be called once
def init_plot(numCycles):
    plt.xlabel('cycles')
    plt.ylabel('grade')   
    plt.title('Grade over time')  
    plt.ylim(0,1)
    plt.xlim(0,numCycles)
 
#Add values to the plot
def addVal(groupName,cycle,grade):
    myData.add(groupName,cycle,grade)
#Mark interesting points on the plot and keep it shown
def end_plot():
    plt.ioff();
    myData.drawFirstMaxGrade(); 
   
    #Make sure the plot is being shown
    plt.show();
#uncomment the following lines to run this script with simple example to make sure #it runs properly regardless of the Specman interaction
#init_plot(300)
#addVal("xx",1,0)
#addVal("yy",1,0)
#addVal("xx",50,0.3)
#addVal("yy",60,0.4)
#addVal("xx",100,0.8)
#addVal("xx",120,0.8)
#addVal("xx",180,0.8)
#addVal("yy",200,0.9)
#addVal("yy",210,0.9)
#addVal("yy",290,0.9)
#end_plot()
 

 In the example we used, we had two interesting entities: packet and state_machine, thus we had two equivalent coverage groups. When running our example connecting to the Python module, we get the following graph which is displayed interactively during the run.

 

    

 

When analyzing this specific example, we can see two things. First, packet gets to a high coverage quite fast and significant part of the run does not contribute to its coverage. On the other hand, something interesting happens relating to state_machine around cycle 700 which suddenly boosts its coverage. The next step would be to try to dump graphic information relating to other entities and see if something noticeable happens around cycle 700.

To run a complete example, you can download the files from: https://github.com/okirsh/Specman-Python/

Do you feel like analyzing the coverage behavior in your environment? We will be happy to hear about your outcomes and other usages of the Python interface.

Orit Kirshenberg
Specman team




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Specman’s Callback Coverage API

Our customers’ tests have become more complex, longer, and consume more resources than before. This increases the need to optimize the regression while not compromising on coverage.

Some advanced customers of Specman use Machine Learning based solutions to optimize the regressions while some use simpler solutions. Based on a request of an advanced customer, we added a new Coverage API in Specman 19.09 called Coverage Callback. In 20.03, we have further enhanced this API by adding more options. Now there are two Coverage APIs that provide coverage information during the run (the old scan_cover API and this new Callback API). This blog presents these two APIs and compares between them while focusing on the newer one.

Before we get into the specifics of each API, let’s discuss what is common between these APIs and why we need them. Typically, people observe the coverage model after the test ends, and get to know the overall contribution of the test to the coverage. With these two APIs, you can observe the coverage model during the test, and hence, get more insight into the test progress.

Are you wondering about what you can do with this information? Let’s look at some examples.

  1. Recognize cases when the test continues to run long after it already reached its coverage goal.
  2. View the performance of the coverage curve. If a test is “stuck” at the same grade for a long time, this might indicate that the test is not very good and is just a waste of resource.

These analyses can be performed in the test itself, and then a test can decide to either stop the run, or change something in it configuration, or – post run. You can also present them visually for some analysis, as shown in the blog: Analyze Your Coverage with Python.

scan_cover API (or “Scanning the Coverage Model”)

With this API you can get the current status for any cover group or item you are interested in at any point in time during the test (by calling scan_cover()). It is very simple to use; however it has performance penalty. For getting the coverage grade of any cover group during the test, you should
1. Trigger the scan_cover at any time when you want the coverage model to be scanned.
2. Implement the scan_cover related methods, such as start_item() and end_bucket(). In these methods, you can query the current grade of group/item/bucket.
The blog mentioned earlier: Analyze Your Coverage with Python describes the details and provides an example.

Callback API

The Callback API enables you to get a callback for a desired cover group(s), whenever it is sampled. This API also provides various query methods for getting coverage related information such as what the current sampled value is. So, in essence, it is similar to scan_cover API, but as the phrase says: “same same but different”:

  1. Callback API has almost no performance penalty while scan_cover API does.
  2. Callback API contains a richer set of query methods that provide a lot of information about the current sampled value (vs just the grade with scan_cover).
  3. Using scan_cover API, you decide when you want to query the coverage information (you call scan_cover), while with the Callback API you query the coverage information when the coverage is sampled (from do_callback). So, scan_cover gives you more flexibility, but you do need to find the right timing for this call.

There is no absolute advantage of either of these APIs, this only depends on what you want to do.  

Callback API details

The Callback API is based on a predefined struct called: cover_sampling_callback. In order to use this API, you need to:

  1. Define a struct inheriting cover_sampling_callback (cover_cb_save_data below)
    1. Extend the predefined do_callback() method. This method is a hook being called whenever any of the cover groups that are registered to the cover_sampling_callback instance is being sampled.
    2. From do_callback() you can access coverage data by using queries such as: is_currently_per_type(), get_current_group_grade() and get_current_cover_group() (as in the example below) and many more such as: get_relevant_group_layers() and get_simple_cross_sampled_bucket_name().
  2. Register the desired cover group(s) to this struct instance using the register() method.

Take a look at the following code:

// Define a coverage callback.
// Its behavior – print to screen the current grade.
struct cover_cb_save_data like cover_sampling_callback {
    do_callback() is only {
       // In this example, we care only about the per_type grade, and not per_instance
       if is_currently_per_type() {           
            var cur_grade : real = get_current_group_grade();
            sys.save_data (get_current_cover_group().get_name(), cur_grade);
        };//if
    };//do_callback()
};// cover_cb_send_data


extend sys {
    !cb : cover_cb_save_data;

   // Instantiate the coverage callback, and register to it two of my coverage groups
    run() is also {
       cb  = new  with {
        var gr1:=rf_manager.get_struct_by_name("packet").get_cover_group("packet_cover");
        .register(gr1);
        var gr2:=rf_manager.get_struct_by_name("sys").get_cover_group("mem_cover");
       .register(gr2);
       };//new  
    };//run()

  save_data(group_name : string, group_grade : real) is {
        //here you either print the values to the screen, update a graph you show or save to a db 
  };// save_data
};//sys

In the blog Analyze Your Coverage with Python mentioned above, we show an example of how you can use the scan_cover API to extract coverage information during the run, and then use the Specman-Python API to display the coverage interactively during the run (using plotting Python library - matplotlib). If you find this usage interesting and you want to use the same example, by the Callback API instead of the scan_cover API, you can download the full example from GIT from here: https://github.com/efratcdn/cover_callback.

Specman Team

 

 




co

BoardSurfers: Footprints for Silicon - Two Steps to Creating PCB Footprints

Longfellow's metaphorical footprints on the sands of time is more profound and eternal no doubt but a footprint for silicon (a form of sand isn't it?) is as important for PCB designers. So, here we will list the steps to create a fo...(read more)



  • Allegro PCB Editor

co

Copying read only problen in cadence virtuoso

Hello, i have a realy mistick thing going with copying libraries in cadence virtuoso,

When i copy straight forwart the whole library it gives me a warning that accsess was denied,but when i go into the library and copy it as a single file, then it goes fine.

another problem is it doesnt show in the massage console  ALL the files which could not be copied.(which is the much bigger problem,becuase i would have to pass threw all the subdirectories to verify if all files are there)

Is there a way to see which files wasnt able to be copied?

Thanks. 




co

Kf parameter testing in spectre under non standart conditions

Hello, i need to test the  parameter Kf under some conditions in subthreshold.i cannot just plot the OP param,becasue i need to derive it under certain conditions.

Spectre(of Cadence) like BSIM(of Berkley) has developed a method for deriving each parameter in their model.

Is there a way to help me with such manual where i can test in cadence virtuoso the Kf parameter shown in the formula bellow?

Thanks.




co

commands that was performed by GUI

hello there, i'm a student studying allegro PCB designer.

There are some commands that i can do with GUI, but i want to know what kind of commands i used so that i can route with commands only(ex) skill).

Is there any file that i can see what kind of commands i used something like log files or command history?

thank you for reading this long boring question.




co

axlDBTextBlockCompact(nil)

I am trying to understand why axlDBTextBlockCompact(nil) on my test case says it can compact the text blocks down to 38, whereas I find only a total of 26 unique text block references in axlDBGetDesign()->text, axlDBGetDesign()->symbols and axlDBGetDesign()->symdefs. Where else are text blocks used besides these three?




co

Updating/replacing/creating new film records

We have many legacy board designs which have non-standard films. I'm writing SKILL code to automatically align a board's film records with our internal standard.

While I'm sure there will be multiple questions, here are the first two I've run into:

1. It seems the polyCutLayer parameter of axlFilmCreate() doesn't work. You can easily see this for yourself. Try typing "axlFilmCreate("test" ?polyCutLayer nil)" on the command window in Allegro. I'm returned "nil", indicating the film could not be created, and I see "*WARNING* (axlFilmCreate): Invalid option type: ?polyCutLayer" in the command window. Just to try a different parameter and see that it works, try "axlFilmCreate("test" ?negative t)". I'm returned a "t" and the film is created. Page 139 of 17.4-2019 algroskill.pdf shows this parameter and I can see it listed if I inspect an existing from from the DB, so what gives? Is the polyCutLayer parameter broken when creating films?

2. In conjunction with the above, if I loop through all current films and use axlDeleteObject() to remove them all, and then try to create new films but give an argument to the polyCutLayer parameter, films containing copper layers seem to be automatically created. There are four films (my test board has four layers) with the ETCH/, PIN/, and VIA CLASS/ subclasses. I am able to manually delete all films and see absolutely no films at all. Is there something weird going on here or is this to be expected for some reason?

I'm running Allegro 17.4s002.




co

Compare the database footprint with library footprint -Skill

I would like to generate the comparison report of database footprint with library footprint if any mismatch available.

Is there a way to take if it possible means can anyone please guide me or share me the skill code please.

Thanks,

Pradeep




co

Skill code to Calculating PCB Real-estate usage using placement boundaries and package keep ins

Other tools allow a sanity check of placement density vs available board space.  There is an older post "Skill code to evaluate all components area (Accumulative Place bound area)"  (9 years ago) that has a couple of examples that no longer work or expired.

This would be useful to provide feedback to schismatic and project managers regarding the component density on the PCB and how it will affect the routing abilities.  Thermal considerations can be evaluated as well 

Has anyone attempted this or still being done externally in spread sheets?




co

How to force the garbage collection

I have a script to handle many polys in memory in allegro. 

But after the completion of the script, 

I run the axlPolyMemUse(), it reports (31922 0 0 55076 252482)

Seems too many polys are still in the memory,and they are not being used. 

So how to delete these polys from the memory? And reclaim the memory?

BTW. I have no skill dev license. So gc() function doesn't work. 

Thanks.




co

Inconsistent behaviour of warn() between Virtuoso and Allegro

For a project, we depend on capturing warnings. This works fine in Virtuoso but behaves differently in Allegro.

In our observations

Virtuoso:

>>> warn("Hello")

*WARNING* Hello

Allegro:

>>> warn("Hello")

*WARNING* Hello

But when we capture the warning:

Virtuoso:

>>> warn("Hello") getWarn()

"Hello"

Allegro:

>>> warn("Hello") getWarn()

"*WARNING* Hello"

This is a Problem for because we put an empty String in the warn and depend on the fact that no Warning results in an empty String but on Allegro the output always begins with *WARNING*

Is there a way to make the behavior consistent in both versions?




co

Breaking a clineseg into multiple segments with SKILL code

Hello All,

May I know if there is a way to breakup a selected clinesegment into a few clinesegments by just using SKILL code

Thanks All




co

Here Is Why the Indian Voter Is Saddled With Bad Economics

This is the 15th installment of The Rationalist, my column for the Times of India.

It’s election season, and promises are raining down on voters like rose petals on naïve newlyweds. Earlier this week, the Congress party announced a minimum income guarantee for the poor. This Friday, the Modi government released a budget full of sops. As the days go by, the promises will get bolder, and you might feel important that so much attention is being given to you. Well, the joke is on you.

Every election, HL Mencken once said, is “an advance auction sale of stolen goods.” A bunch of competing mafias fight to rule over you for the next five years. You decide who wins, on the basis of who can bribe you better with your own money. This is an absurd situation, which I tried to express in a limerick I wrote for this page a couple of years ago:

POLITICS: A neta who loves currency notes/ Told me what his line of work denotes./ ‘It is kind of funny./ We steal people’s money/And use some of it to buy their votes.’

We’re the dupes here, and we pay far more to keep this circus going than this circus costs. It would be okay if the parties, once they came to power, provided good governance. But voters have given up on that, and now only want patronage and handouts. That leads to one of the biggest problems in Indian politics: We are stuck in an equilibrium where all good politics is bad economics, and vice versa.

For example, the minimum guarantee for the poor is good politics, because the optics are great. It’s basically Garibi Hatao: that slogan made Indira Gandhi a political juggernaut in the 1970s, at the same time that she unleashed a series of economic policies that kept millions of people in garibi for decades longer than they should have been.

This time, the Congress has released no details, and keeping it vague makes sense because I find it hard to see how it can make economic sense. Depending on how they define ‘poor’, how much income they offer and what the cost is, the plan will either be ineffective or unworkable.

The Modi government’s interim budget announced a handout for poor farmers that seemed rather pointless. Given our agricultural distress, offering a poor farmer 500 bucks a month seems almost like mockery.

Such condescending handouts solve nothing. The poor want jobs and opportunities. Those come with growth, which requires structural reforms. Structural reforms don’t sound sexy as election promises. Handouts do.

A classic example is farm loan waivers. We have reached a stage in our politics where every party has to promise them to assuage farmers, who are a strong vote bank everywhere. You can’t blame farmers for wanting them – they are a necessary anaesthetic. But no government has yet made a serious attempt at tackling the root causes of our agricultural crisis.

Why is it that Good Politics in India is always Bad Economics? Let me put forth some possible reasons. One, voters tend to think in zero-sum ways, as if the pie is fixed, and the only way to bring people out of poverty is to redistribute. The truth is that trade is a positive-sum game, and nations can only be lifted out of poverty when the whole pie grows. But this is unintuitive.

Two, Indian politics revolves around identity and patronage. The spoils of power are limited – that is indeed a zero-sum game – so you’re likely to vote for whoever can look after the interests of your in-group rather than care about the economy as a whole.

Three, voters tend to stay uninformed for good reasons, because of what Public Choice economists call Rational Ignorance. A single vote is unlikely to make a difference in an election, so why put in the effort to understand the nuances of economics and governance? Just ask, what is in it for me, and go with whatever seems to be the best answer.

Four, Politicians have a short-term horizon, geared towards winning the next election. A good policy that may take years to play out is unattractive. A policy that will win them votes in the short term is preferable.

Sadly, no Indian party has shown a willingness to aim for the long term. The Congress has produced new Gandhis, but not new ideas. And while the BJP did make some solid promises in 2014, they did not walk that talk, and have proved to be, as Arun Shourie once called them, UPA + Cow. Even the Congress is adopting the cow, in fact, so maybe the BJP will add Temple to that mix?

Benjamin Franklin once said, “Democracy is two wolves and a lamb voting on what to have for lunch.” This election season, my friends, the people of India are on the menu. You have been deveined and deboned, marinated with rhetoric, seasoned with narrative – now enter the oven and vote.

The India Uncut Blog © 2010 Amit Varma. All rights reserved.
Follow me on Twitter.




co

IMC : fsm coding style not auto extracted/Identified by IMC

Hi,

I've vhdl block containing fsm . IMC not able to auto extract the state machine coded like this:

There is a intermediate state state_mux  between next_state & state.

Pls. help in guiding IMC how to recognize this FSM coding style? 

 

Snipped of the fsm code:

----------------------------------------------------------------------------------------------------------------------------------------------

               type state_type is (ST_IDLE, ST_ADDRESS, ST_ACK_ADDRESS, ST_READ, ST_ACK_READ, ST_WRITE, ST_ACK_WRITE, ST_IDLE_BYTE);

               signal state : state_type;

               signal state_mux : state_type;

               signal next_state : state_type;

process(state_mux, start)

         begin

               next_state <= state_mux;

               next_count <= (others => '0');

           case (state_mux) is

                 when ST_IDLE => 

                            if(start = '1') then

                                 next_state <= ST_ADDRESS;

                              end if;

            when ST_ADDRESS =>

   …………….

          when others => null;

         end case;

     end process;

 

process(scl_clk_n, active_rstn)

               begin

                      if(active_rstn = '0') then

                           state <= ST_IDLE after delay_f;

                  elsif(scl_clk_n'event and scl_clk_n = '1') then

                             state <= next_state after delay_f;

                            end if;

end process;

 

process(state, start)

               begin

                     state_mux <= state;

               if(start = '1') then

                       state_mux <= ST_IDLE;

                              end if;

               end process;

Thanks

Raghu




co

IMC: toggle coverage for package array

Hello!

I have input signal like this  ->  input  wire [ADM_NUM-1:0][1:0] m_axi_ddr_rresp.

When i want to analyze coverage from IMC  this signal not covered!

Can i collect coverage for this signal?

 




co

How do we use the concept of Save and Restore during real developing(debugging)???/

Hi All,

I'm trying to understand checkpoint concept. When I found save and restart concept in cdnshelp, There is just describing about "$save" and "xrun -r "~~~".

and I found also the below link about save restart and it saves your time.

But I can't find any benefits from my experiment from save&restart article( I fully agree..the article)

Ok, So I'v got some experiment  Here.

1. I declared $save and got the below result as I expected within the simple UVM code.

In UVM code...

$display("TEST1");
$display("TEST2");
$save("SAVE_TEST");
$display("TEST3");
$display("TEST4");

And I restart at "SAVE_TEST" point by xrun -r "SAVE_TEST", I've got the below log

xcelium> run
TEST3
TEST4

Ok, It's Good what I expected.(The concept of Save and Restore is simple: instead of re-initializing your simulation every time you want to run a test, only initialize it once. Then you can save the simulation as a “snapshot” and re-run it from that point to avoid hours of initialization times. It used to be inconvenient. I agree..)

2. But The Problem is that I can't restart with modified code. Let's see the below example.

I just modified TEST5 instead of "TEST3"

$display("TEST1");
$display("TEST2");
$save("SAVE_TEST");
$display("TEST5"); //$display("TEST3");
$display("TEST4");

and I rerun with xrun -r "SAVE_TEST", then I've got the same log

xcelium> run
TEST3
TEST4

There is no "TEST5". Actually I expected "TEST5" in the log.From here We know $save can't support partially modified code after $save. 

Actually, through this, we can approach to our goal about saving developing time. 

So I want to know Is there any possible way that instead of re-initializing our simulation every time we want to run a test, only initialize it once and keep developing(debugging) our code ?

If we do, Could you let me know the simple example?




co

Can't collect AXI4 burst_started coverage

I have a problem connected with my AXI4 coverage.

I enable coverage collection in AXI4 

      set_config_int("axi4_active_slave_agent_0.monitor.coverModel", "burst_started_enable", 1);
      set_config_int("axi4_active_slave_agent_0.monitor.coverModel", "coverageEnable", 1);

but i don't have a result.

I think the problem in Callback, but i try to connect all callback and i don't have positive result.

Can you help me?




co

Coverage error

Hi  all,

          I am getting this warning in while generating the coverage report, can you help me to clear this warning?

ncsim: *W,COVOPM: Coverage configuration file command "set_covergroup -optimize_model" can be specified to improve the performance and scalability of coverage model containing SV covergroups. It may be noted that subsequent merging of a coverage database saved with this command and a coverage database saved without this command is not allowed.




co

Running xrun command in vsif file

Hi,

I found a basic Specman E/Verilog program at http://www.asic-world.com/examples/specman/memory.html and I would like to run it through a vsif file, with vManager.

I'm able to run it, without problems, with this command : xrun -Q -unbuffered '-timescale' '1ns/1ns' '-access' '+rw' memory_tb.v mem_tb_top.e test_write_read_all.e.

I wrote a first vsif which look like this:

---- vm_basic.vsif -----

session vm_basic {
        top_dir : /home/cadence/xrunTest/;
        output_mode: terminal;
};

group basic {
        test test {
                run_script: xrun -Q -unbuffered '-timescale' '1ns/1ns' '-access' '+rw' memory_tb.v mem_tb_top.e test_write_read_all.e
        };
};

----------------------------

This solution didn't work due to the prompt change with xrun, and I have no clue how to manage this issue.

Have you any idea?

Best regards,

Yohan




co

How to refer the library compiled by INCISIVE 13.20 in Xcelium 19.30

Hi,

I am facing this elaboration error when using Xcelium:

Command>

    xmverilog -v200x +access+r +xm64bit -f vlist -reflib plib -timescale 1ns/1ps

Log>

    xmelab: *E,CUVMUR (<name>.v,538|18): instance 'LUTP0.C GLAT3' of design unit 'tlatntscad12' is unresolved in 'worklib.LUTP0:v'.

I guess the plib was not referred to as the simulation configuration because the tlatntscad12 is included in plib.

The plib is compiled by INCISIVE 13.20 and I am using the Xcelium 19.30.

Please tell me the correct command on how to refer to the library directory compiled by different versions.

Thank you,




co

Is it possible to get a diff between two coverage databases in IMC?

I'm in the process of weeding a regression test list. I have a coverage database from the full regression list and would like to diff it with the coverage database from the new reduced regression test list. If possible I would than like to trace back any buckets covered with the full list, but not with the partial list, into the original tests that covered them.

Is that possible using IMC? if not, is it possible to do from Specman itself?

(Note that we're not using vManager)

Thanks,

Avidan




co

IC Packagers: Identify Your Components

We’ve all seen bar codes and the more modern QR codes. They’re everywhere you go – items at the grocery store, advertisements and posters, even on websites. Did you know that, with the productivity toolbox in Allegro Package Designe...(read more)



  • Allegro Package Designer
  • Allegro PCB Editor

co

IC Packagers: Shape Connectivity in the Allegro Data Model

Those who work in the IC Packaging design space have some unique challenges. We bridge between the IC design world (90/45-degree traces with rectangular and octagonal pins) and the PCB domain (any-angle routing, filled planes, and a multitude of pad ...(read more)



  • Allegro Package Designer
  • Allegro PCB Editor

co

Why the Autorouter use Via to connect GND and VCC pins to Shape Plane

Here are two screen capture of Before and After Autorouting my board. Padstacks have all been revised and corrected. The Capture Schematic is correct. All Footprints have been verified after Padstack revision. a new NETLIST generation have been done after some corrections made in Capture. I have imported the new Logic. I revised my Layout Cross Section as such: TOP, GND, VCC, BOTTOM. Both VCC and GND shapes have been assigned to their respective logical GND and VCC Nets (verified). Yet, I still have the Autorouter to systematically use extra vias to make GND and VCC connections to the VCC and GND planes. Where a simple utilisation of the part padstack inner layer would have been indicated. What Im I missing ?




co

Capture Constraint Man anger

Is anyone else using Constraint Manager within Capture? This is my first time using it. I'm finding that it is occasionally changing some of my constraint values in Allegro. It seems random. 




co

Error: CMFBC-1 The schematic and the layout constraints were not synchronized

Hi, I am in the middle of a design and had no problem going back and forth between schematics and layout. Now I am getting the error message below. I am using Cadence 17.2.

ERROR: Layout database has probably been reverted to an earlier version than that, which was used in the latest flow or the schematic database was synchronized with another board.

The basecopy file generated by the last back-to-front flow not found.

ERROR: Layout database has probably been reverted to an earlier version than that, which was used in the latest flow or the schematic database was synchronized with another board.

The basecopy file generated by the last back-to-front flow not found.

Error: CMFBC-1: The schematic and the layout constraints were not synchronized as the changes done since the last sync up could not be reconciled. Syncing the current version of the schematic or layout databases with a previous version would result in this issue. The  constraint difference report is displayed.

Continuing with "changes-only" processing may result in incorrect constraint updates.

Thanks for your input

Claudia




co

New comer, need help with VIA drill size change

Greeting to all:

I am new in this tool, only 2 weeks. Trying to create a new Via with smaller size drill hole from exiting 13 mils size to 10 mils size. I got the message as imaged below. Any advise what to do?  Thanks in advance.

 




co

Is it possible to find or create a Pspice model for the JT3028, LD7552 components?

I would like to add these components to the component bank in ORCAD simulation. Even an accessible or free course that explained how to create these components.




co

Create a new Constraint Group or Constraint Class ?

When in Constraint Manager, Physical Domain, one can create a new Physical Constraint Class defining specific attributes for a custom rule set. One can then assing this new rule set to a set of nets. To do that it is instructed to create a new Net Class with menu Objects > Create > Net Class. Also on that same menu is available Net Group. Both options create a group that appear in the Constraint Manager Objects Name Column. I have triied both  options and cant really see the difference. 

The Question: What is the difference between creating a Net Class and a Net Group ?  What are the implications ?

Thanks for your help.




co

Allegro design entry DHL, pin swaps , export without exporting constraints, back annotate.

Hi,

I have a new customer that uses Allegro Design entry HDL for the schematic and have a few questions.

1. How do you get pin/gate swaps into the symbols in the schematic ?

2. How do you transfer them to the pcb editor ?

3. How do you back annotate the swaps from the pcb editor to the schematic ?

4. How do you stop the export/Import physical from updating the constraints in the pcb file ? 




co

Welcome! Please use this forum to upload your code

Please include a brief summary of how to use it.




co

e-code: Macro example code for Team Specman blog post

Hi everybody,

 

The attached package is a tiny code example with a demo for an upcoming Team Specman blog post about writing macros.

 

Hilmar




co

IntelliGen Statistics Metrics Collection Utilility

As noted in white papers, posts on the Team Specman Blog, and the Specman documentation, IntelliGen is a totally new stimulus generator than the original "Pgen" and, as a result, there is some amount of effort needed to migrate an existing verification environment to fully leverage the power of IntelliGen.  One of the main steps in migrating code is running the linters on your code and adressing the issues highlighted. 

Included below is a simple utility you can include in your environment that allows you to collect some valuable statistics about your code base to allow you to better gauge the amount of work that might be required to migrate from Pgen to IntelliGen.  The ICFS statistics reported are of particular benefit as the utility not only identifies the approximate number of ICFSs in the environment, it also breaks the total number down according to generation contexts (structs/units and gen-on-the-fly statements) allowing you to better focus your migration efforts. 

IMPORTANT: Sometimes a given environment can trigger a large number of IntelliGen linting messages right off the bat.  Don't let this freak you out!  This does not mean that migration will be a long effort as quite often some slight changes to an environment remove a large number of identified issues.  I recently encountered a situation where a simple change to three locations in the environment, removed 500+ ICFSs!

The methods included in the utility can be used to report information on the following:
- Number of e modules
- Number of lines in the environment (including blanks and comments)
- Number and type of IntelliGen Guidelines linting messages
- Number of Inconsistently Connected Field Sets (ICFSs)
- Number of ICFS contexts and how many ICFSs per context
- Number of soft..select overlays found in the envioronment
- Number of Laces identified in the environment


To use the code below, simply load it before/after loading e-code and then
you can execute any of the following methods:

- sys.print_file_stats()             : prints # of lines and files
- sys.print_constraint_stats()   : prints # of constraints in the environment
- sys.print_guideline_stats()    : prints # of each type of linting message
- sys.print_icfs_stats()            : prints # of ICFSs, contexts and #ICFS/context
- sys.print_soft_select_stats() : prints # of soft select overlay issues
- sys.print_lace_stats()           : *Only works for SPMNv6.2s4 and later* prints # of laces identified in the environment

Each of the above calls to methods produces it's own log files (stored in the current working directory) containing relevant information for more detailed analysis.
- file_stats_log.elog : Output of "show modules" command
- constraint_log.elog : Output of the "show constraint" command
- guidelines_log.elog : Output of "gen lint -g" (with notification set to MAX_INT in order to get all warnings)
- icfs_log.elog       : Output of "gen lint -i" command
- soft_select_log.elog: Output of the "gen lint -s" command
- lace_log.elog       : Output of the "show lace" command


Happy generating!

Corey Goss




co

ctags for e code, Vim compatible

In a nutshell, tags allows you to navigate through program code distributed over multiple files effectively. e.g if you see a function call or a struct in e-code and want to "jump" to the definition (which may be in a different file) then you just hit CTRL+] in Vim! Pressing CTRL+t will take you back where you came from. Check out http://vim.wikia.com/wiki/Browsing_programs_with_tags#Using_tags if you want to learn more about how to use tags with Vim.

This utility can generate tags file for your e files. It can either walk through e import order, a directory recursively or all directories on SPECMAN_PATH recursively! The tags file will have tags for struct, unit, types, events, defines, fields, variables, etc.

For help and some examples, just run ctags4e -help.

 

 




co

Creating transition coverage bins using a queue or dynamically

I want to write a transition coverage on an enumeration. One of the parts of that transition is a queue of the enum. I construct this queue in my constructor. Considering the example below, how would one go about it.

In my coverage bin I can create a range like this A => [queue1Enum[0]:queue1Enum[$]] => [queue2Enum[0]:queue2Enum[$]]. But I only get first and last element then.

typedef enum { red, d_green, d_blue, e_yellow, e_white, e_black } Colors;
 Colors dColors[$];
 Colors eColors[$];
 Lcolors = Colors.first();
 do begin
  if (Lcolors[0].name=='d') begin
   dColors.push_back(Lcolors);
  end
  if (Lcolors[0].name=='e') begin
   eColors.push_back(Lcolors);
  end
 end while(Lcolors != Lcolors.first())

 covergroup cgTest with function sample(Colors c);
   cpTran : coverpoint c{
      bins t[] = (red => dColors =>eColors);   
   }
 endgroup

bins t[] should come out like this(red=>d_blue,d_green=>e_yellow,e_white)

 




co

Creating cover items for sparse values/queue or define in specman

Hello,

I have a question I want to create a cover that consists a sparse values, pre-computed (a list or define) for example l = {1; 4; 7; 9; 2048; 700} I'd like to cover that data a (uint(bits:16)) had those values, Any suggestion on how to achieve this, I'd prefer to stay away from macros, and avoid to write a lot of code

struct inst {

  data :uint(bits:16);
  opcode :uint(bits:16);
  !valid_data : list of uint(bits:16) = {0; 12; 10; 700; 890; 293;};
  event data_e;
  event opcode_e;

  cover data_e is {
     item data using radix = HEX, ranges = {
     //I dont want to write all of this
     range([0], "My range1");
     range([10], "My range2");
     //... many values in between
    range([700], "My rangen");
    };


    item opcode;


   cross data, opcode;
};

post_generate() is also {
    emit data_e;
};
};




co

convert ircx to ict or emDataFile for Voltus-fi

Hi,

I want to convert ircx file(which from TSMC) to ict or emDataFile for Voltus-fi.

I tried many way, but I can not make it.

and I  do not installed QRC.

below is some tools installed my server. 

IC617-64b.500.21 is used.