Hi All.

I put together a small Perl script to generate vr_ad register definitions from SPIRIT (IP-XACT) XML.
If you've got not idea what IP-XACT is, have a look here http://www.spiritconsortium.org/, then start pestering your design manager to use it :-)

The script can filter out registers and override R/W access types if needed.

An example XML file is included with the package so that you can play with it, and there's a detailed README.txt as well.

Here's an example of the generated e code:

// Automatically generated from xdmac.xml
// DO NOT EDIT, or your changes may be lost
<'

import vr_ad/e/vr_ad_top;

// Component = XDMAC
// memoryMap = xdmac
extend vr_ad_map_kind : [XDMAC];

// addressBlock = dma_eth
extend vr_ad_reg_file_kind : [DMA_ETH];

extend DMA_ETH vr_ad_reg_file {
  keep size == 20;
  keep addressing_width_in_bytes == 4;
};

// Register = command
// Reset    = 0x00
reg_def COMMAND DMA_ETH 0x0 {
  // Field resv3 = command[31:29]
  reg_fld resv3 : uint(bits:3) : R : 0 : cov ;
  // Field transfer_size = command[28:19]
  reg_fld transfer_size : uint(bits:10) : RW : 0 : cov ;
  // Field dma_transfer_target = command[18:14]
  reg_fld dma_transfer_target : uint(bits:5) : RW : 0 : cov ;
  // Field resv2 = command[13:10]
  reg_fld resv2 : uint(bits:4) : R : 0 : cov ;
  // Field transmit_receive = command[9:9]
  reg_fld transmit_receive : uint(bits:1) : RW : 0 : cov ;
  // Field resv1 = command[8:5]
  reg_fld resv1 : uint(bits:4) : R : 0 : cov ;
  // Field dest_address_enable = command[4:4]
  reg_fld dest_address_enable : uint(bits:1) : RW : 0 : cov ;
  // Field source_address_enable = command[3:3]
  reg_fld source_address_enable : uint(bits:1) : RW : 0 : cov ;
  // Field word_size = command[2:0]
  reg_fld word_size : uint(bits:3) : R : 0 : cov ;
};

// Register = queue_exec
// Reset    = 0x00
reg_def QUEUE_EXEC DMA_ETH 0x10 {
  // Field resv = queue_exec[31:1]
  reg_fld resv : uint(bits:31) : R : 0 : cov ;
  // Field exec = queue_exec[0:0]
  reg_fld exec : uint(bits:1) : RW : 0 : cov ;
};

extend XDMAC vr_ad_map {
  dma_eth : DMA_ETH vr_ad_reg_file;

  post_generate() is also {
    add_with_offset(0x00, dma_eth);
    dma_eth.reset();
  };
}
'>

Any comments, please feed them back to me so I can enhance the script.
Note that this forum forces me to post a .zip file rather than .tgz, please be careful to unpack the file under Linux, not Windows, else the DOS linefeeds will corrupt the Perl and XML files.

Steve

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

Hello All,

Following is the einstein's puzzle solved by cadence Incisive92  (solved in less than 3 seconds -> FAST!!!!!!)

Thanks,

Vinay Honnavara

Verification engineer at Keyu Tech

vinayh@keyutech.com

 // Author: Vinay Honnavara

// Einstein formulated this problem : he said that only 2% in the world can solve this problem
// There are 5 different parameters each with 5 different attributes
// The following is the problem

// -> In a street there are five houses, painted five different colors (RED, GREEN, BLUE, YELLOW, WHITE)

// -> In each house lives a person of different nationality (GERMAN, NORWEGIAN, SWEDEN, DANISH, BRITAIN)

// -> These five homeowners each drink a different kind of beverage (TEA, WATER, MILK, COFFEE, BEER),

// -> smoke different brand of cigar (DUNHILL, PRINCE, BLUE MASTER, BLENDS, PALL MALL)

// -> and keep a different pet (BIRD, CATS, DOGS, FISH, HORSES)


///////////////////////////////////////////////////////////////////////////////////////
// *************** Einstein's riddle is: Who owns the fish? ***************************
///////////////////////////////////////////////////////////////////////////////////////

/*
Necessary clues:

1. The British man lives in a red house.
2. The Swedish man keeps dogs as pets.
3. The Danish man drinks tea.
4. The Green house is next to, and on the left of the White house.
5. The owner of the Green house drinks coffee.
6. The person who smokes Pall Mall rears birds.
7. The owner of the Yellow house smokes Dunhill.
8. The man living in the center house drinks milk.
9. The Norwegian lives in the first house.
10. The man who smokes Blends lives next to the one who keeps cats.
11. The man who keeps horses lives next to the man who smokes Dunhill.
12. The man who smokes Blue Master drinks beer.
13. The German smokes Prince.
14. The Norwegian lives next to the blue house.
15. The Blends smoker lives next to the one who drinks water.
*/




typedef enum bit [2:0]  {red, green, blue, yellow, white} house_color_type;
typedef enum bit [2:0]  {german, norwegian, brit, dane, swede} nationality_type;
typedef enum bit [2:0]  {coffee, milk, water, beer, tea} beverage_type;
typedef enum bit [2:0]  {dunhill, prince, blue_master, blends, pall_mall} cigar_type;
typedef enum bit [2:0]  {birds, cats, fish, dogs, horses} pet_type;




class Einstein_problem;

    rand house_color_type house_color[5];
    rand nationality_type nationality[5];
    rand beverage_type beverage[5];
    rand cigar_type cigar[5];
    rand pet_type pet[5];
        rand int arr[5];
    
    constraint einstein_riddle_solver {
    
        
    
        foreach (house_color[i])
            foreach (house_color[j])
               if (i != j)
                house_color[i] != house_color[j];
        foreach (nationality[i])
            foreach (nationality[j])
               if (i != j)
                nationality[i] != nationality[j];
        foreach (beverage[i])
            foreach (beverage[j])
               if (i != j)
                beverage[i] != beverage[j];
        foreach (cigar[i])
            foreach (cigar[j])
               if (i != j)
                cigar[i] != cigar[j];
        foreach (pet[i])
            foreach (pet[j])
               if (i != j)
                pet[i] != pet[j];
    
    
        //1) The British man lives in a red house.
        foreach(nationality[i])
                (nationality[i] == brit) -> (house_color[i] == red);
                
        
        //2) The Swedish man keeps dogs as pets.
        foreach(nationality[i])
                (nationality[i] == swede) -> (pet[i] == dogs);
                
                
        //3) The Danish man drinks tea.        
        foreach(nationality[i])
                (nationality[i] == dane) -> (beverage[i] == tea);
        
        
        //4) The Green house is next to, and on the left of the White house.
        foreach(house_color[i])        
                 if (i<4)
                    (house_color[i] == green) -> (house_color[i+1] == white);
        
        
        //5) The owner of the Green house drinks coffee.
        foreach(house_color[i])
                (house_color[i] == green) -> (beverage[i] == coffee);
                
        
        //6) The person who smokes Pall Mall rears birds.
        foreach(cigar[i])
                (cigar[i] == pall_mall) -> (pet[i] == birds);
        
        
        //7) The owner of the Yellow house smokes Dunhill.
        foreach(house_color[i])
                (house_color[i] == yellow) -> (cigar[i] == dunhill);
        
        
        //8) The man living in the center house drinks milk.
        foreach(house_color[i])
                if (i==2) // i==2 implies the center house (0,1,2,3,4) 2 is the center
                    beverage[i] == milk;
        
        
        
        //9) The Norwegian lives in the first house.
        foreach(nationality[i])        
                if (i==0) // i==0 is the first house
                    nationality[i] == norwegian;
        
        
        
        //10) The man who smokes Blends lives next to the one who keeps cats.
        foreach(cigar[i])        
                if (i==0) // if the man who smokes blends lives in the first house then the person with cats will be in the second
                    (cigar[i] == blends) -> (pet[i+1] == cats);
        
        foreach(cigar[i])        
                if (i>0 && i<4) // if the man is not at the ends he can be on either side
                    (cigar[i] == blends) -> (pet[i-1] == cats) || (pet[i+1] == cats);
        
        foreach(cigar[i])        
                if (i==4) // if the man is at the last
                    (cigar[i] == blends) -> (pet[i-1] == cats);
        
        foreach(cigar[i])        
                if (i==4)
                    (pet[i] == cats) -> (cigar[i-1] == blends);
        
        
        //11) The man who keeps horses lives next to the man who smokes Dunhill.
        foreach(pet[i])
                if (i==0) // similar to the last case
                    (pet[i] == horses) -> (cigar[i+1] == dunhill);
        
        foreach(pet[i])        
                if (i>0 & i<4)
                    (pet[i] == horses) -> (cigar[i-1] == dunhill) || (cigar[i+1] == dunhill);
                    
        foreach(pet[i])        
                if (i==4)
                    (pet[i] == horses) -> (cigar[i-1] == dunhill);
                    


        //12) The man who smokes Blue Master drinks beer.
        foreach(cigar[i])
                (cigar[i] == blue_master) -> (beverage[i] == beer);
        
        
        //13) The German smokes Prince.
        foreach(nationality[i])        
                (nationality[i] == german) -> (cigar[i] == prince);
        

        //14) The Norwegian lives next to the blue house.
        foreach(nationality[i])
                if (i==0)
                    (nationality[i] == norwegian) -> (house_color[i+1] == blue);
        
        foreach(nationality[i])        
                if (i>0 & i<4)
                    (nationality[i] == norwegian) -> (house_color[i-1] == blue) || (house_color[i+1] == blue);
        
        foreach(nationality[i])        
                if (i==4)
                    (nationality[i] == norwegian) -> (house_color[i-1] == blue);
        

        //15) The Blends smoker lives next to the one who drinks water.            
        foreach(cigar[i])            
                if (i==0)
                    (cigar[i] == blends) -> (beverage[i+1] == water);
        
        foreach(cigar[i])        
                if (i>0 & i<4)
                    (cigar[i] == blends) -> (beverage[i-1] == water) || (beverage[i+1] == water);
                    
        foreach(cigar[i])        
                if (i==4)
                    (cigar[i] == blends) -> (beverage[i-1] == water);
        
    } // end of the constraint block
    


    // display all the attributes
    task display ;
        foreach (house_color[i])
            begin
                $display("HOUSE : %s",house_color[i].name());
            end
        foreach (nationality[i])
            begin
                $display("NATIONALITY : %s",nationality[i].name());
            end
        foreach (beverage[i])
            begin
                $display("BEVERAGE : %s",beverage[i].name());
            end
        foreach (cigar[i])
            begin
                $display("CIGAR: %s",cigar[i].name());
            end
        foreach (pet[i])
            begin
                $display("PET : %s",pet[i].name());
            end
        foreach (pet[i])
            if (pet[i] == fish)
                $display("THE ANSWER TO THE RIDDLE : The %s has %s ", nationality[i].name(), pet[i].name());
    
    endtask // end display
    
    
endclass




program main ;

    initial
        begin
            Einstein_problem ep;
            ep = new();
            if(!ep.randomize())
                $display("ERROR");
            ep.display();
        end
endprogram // end of main

        

ncsim will consume an increasing ammount of memory when a function has an output port that return an associative array which was not initialized. My simulator version is 12.10-s011.

Below is a code example to reproduce the failure. The code is inside a class (uvm_object):

function void a_function(output bit ret_val[int]);

// empty 

endfunction : get_cov

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

I'm trying to set up a VHDL-AMS simulation, so I made a new cell, selected the vhdlamstext type, and copied some example from the web. But when I hit the save and compile button, I first got the following NOLSTD error:

https://www.edaboard.com/showthread.php?27832-Simulating-a-VHDL-design-in-ldv5-1

So I added said file to my cds.lib and tried again. But now I'm getting this:

ncvhdl_p: *F,DLUNNE: Can't find STANDARD at /cadappl/ictools/cadence_ic/6.1.7.721/tools/inca/files/STD.

If I go over to the Library Browser, it indeed shows that the library is completely empty. Properties show it has the following files attached.

In the file system I've also found a STD.src folder. Is there a way to recompile the library properly? Supposedly this folder includes precompiled versions, but looks like not really.

Hi,

I am currently struggling with measuring the delay between two clocks with a sufficient accuracy. The reference one is a fixed-phase clock, and the other one is a squared clock resulting of a circuit (kind of PLL) synthesis.
As I need to run a large amount of Monte-Carlo simulations in transient noise, I need to improve the simulation speed, while keeping a satisfactory delay measurement accuracy (<0.1ps), more specifically at 0V-crossings of the differential clocks. So I cannot simply set a max timestep <0.1ps as it would be far too long to simulate.
To sum up, I would need a very relaxed timestep on clock up and down levels, and a very short timestep only at rise/fall transitions.

For this purpose, I wrote a Verilog-A script
- using a timmer function to accurately emulate the reference clock 0V-crossing times (and get the related times with $abstime)
- using @(cross to get the 0V-crossing times of the synthesized clock: but this is not accurate enough (I see simulation noise around 3ps in Conservative). Indeed, the "cross" event occures at the simulation time following the effective 0V-crossing time; this could be sometimes >3ps, far not enough accurate for my purpose.
- I have tried to replace the cross with the "above" function, but it hasn't changed anything, whatever the time_tol value I put (<0.1ps for instance), the result is the same as with the "cross" function and the points are larger than >>0.1ps, weirdly.

So I have decided to give up Verilog-A to measure the delay between my two clocks.
I am currently trying to use the "delay" function of the Cadence Calculator as I guess it will "extrapolate" the time between two simulation points and therefore give a more accurate measurement of the 0V-crossing events, but when I try to compute the delay difference between the synthesized clock and the reference clock, it returns "0".

...

Could you please give me hints to dramatically improve my 0V-crossing time measurements while relaxing the simulation time?
- either by helping me in writing a more suitable Verilog-A script
- or by helping me in using the "delay" function of the calculator
- or maybe by providing me a "magic" Skill function?
Using AMS+Multithread simulator...

Thanks a lot in advance for your help and best regards.

Hi, 

I want my layout verified by Quantus QRC. But, I can't find the tool bar on the option list ( as show in the picture)

I have tried to install EXT182 and configured it with iscape already, and also make some path settings on .bashrc, .cshrc. But, when I re-source .cshrc and run virtuoso again, I just can't find the toolbar. 

If you have some methods, please let me know.

Thanks a lot!

Appreciated

My virtuoso version is: ICADV12.3

Hi,

I tried to open my layout by Library Manager, but the Virtuoso CIW window sometimes pops up the follow WARNING messages( as picture depicts). Thus, layout can't open.

Sometimes, I try to reconfigure ICADV12.3 by the iscape and restart my VM and then it incredibly works! But, often not!

So, If anyone knows what it is going on. Please let me know! Thanks!

Appreciated so much   

Hello,

I find a strange issue when using design variable -> right-click -> copy from cellview in assembler. Cadence version is IC618-64b. 500.9

In fact, I set the value of variable (e.g., AAA = 100), then after I right-click -> copy from cellview, AAA's is updated to other value. In my opinion "copy from cellview" should only update the missing variable to the list, but not change any variable value. 

Is there any mechanism could change variable value when using "copy from cellview"?

Thanks

Dear All,
When I want to start simulation with spectre the error says:
Fatal error: Illegal library definition found in netlist
I set the model file correctly, but I don't know why it errors!
I opened the ADE>>Setup>>Model library
and I tried to modify the path of models file (SCS files)
It gives me "Illegal library definition found in netlist"
Thanks.

Hi,

This question is related to the constraint measurement criteria used by the Liberate inside view. I am trying to characterize a specific D flip-flop for low voltage operation (0.6V) using Cadence Liberate (V16). 

When the "define_arcs" are not explicitly specified in the settings for the circuit (but the input/outputs are indeed correct in define_cell), the inside view seems to probe an internal node (i.e. master latch output)  for constraint measurements instead of the Q output of the flip flop. So to force the tool to probe Q output I added following coder in constraint arcs :

# constraint arcs from CK => D
define_arc
-type hold
-vector {RRx}
-related_pin CP
-pin D
-probe Q
DFFXXX

define_arc
-type hold
-vector {RFx}
-related_pin CP
-pin D
-probe Q
DFFXXX

define_arc
-type setup
-vector {RRx}
-related_pin CP
-pin D
-probe Q
DFFXXX

define_arc
-type setup
-vector {RFx}
-related_pin CP
-pin D
-probe Q
DFFXXX

with -probe Q liberate identifies Q as the output, but uses Glitch-Peak criteria instead of delay degradation method. So what could be the exact reason for this unintended behavior ? In my external (spectre) spice simulation, the Flip-Flop works well and it does not show any issues in the output delay degradation when the input sweeps.

Thanks

Anuradha

Before I ask this, I am aware that I can output an s-parameter file from an SP analysis.

I'm wondering if there is a simple way of creating an s-parameter model of a component.

As an example, if I have an S-parameter model that has 200 ports and 150 of those ports are to be connected to passive components and the remaining 50 ports are to be connected to active components, I can simplify the model by connecting the 150 passive components, running an SP analysis, and generating a 50 port S-parameter file.

The problem is that this is cumbersome. You've got to wire up 50 PORT components and then after generating the s50p file, create a new cellview with an nport component and connect the 50 ports with 50 new pins.

Wiring up all of those port components takes quite a lot of time to do, especially as the "choosing analyses" form adds arrays in reverse (e.g. if you click on an array of PORT components called X<0:2> it will add X<2>, X<1>, X<0> instead of in ascending order) so you have to add all of them to the analyses form manually.

Is any way of taking a schematic and running some magic "generate S-Parameter cellview from schematic cellview"  function that automates the whole process?

Cadence Liberate Trio Characterization Suite, ARM-based Graviton Processors, and Amazon Web Services (AWS) Cloud have joined forces to cater to the High-Performance Computing, Machine Learning/Artificial Intelligence, and Big Data Analytics sectors. (read more)

Let’s review a key characteristic feature of Cadence Liberate AMS Mixed-Signal Characterization that offers to you ease of use along with many other benefits like automation of standard Liberty model creation and improvement of up to 20X throughput.(read more)

In this blog, I will brief you about two very useful Rapid Adoption Kits (RAKs) for Liberate LV Library Validation.(read more)

Optimizing power can be a very convoluted and crucial process. To make design chips meet throughput goals along with optimal power consumption, you need to plan right from the beginning! (read more)

Hi Everyone,

Many of you would have heard about the Cadence Stylus Common UI and are wondering what it is and what the advantages might be to use it versus legacy UI.

The webinar answers the following questions:

• Why did Cadence develop Stylus UI and what is Stylus Common UI?
• How does someone invoke and use the Stylus Common UI?
• What are some of the important and useful features of the Stylus Common UI?
• What are the key ways in which the Stylus Common UI is different from the default UI?​

If you want to learn more about Stylus UI in the context of implementation, view the 45-minute recorded webinar on the Cadence support site.

Related Resource

Innovus Block Implementation with Stylus Common UI

Vinita Nelson

The Cadence® Genus  Synthesis Solution, Innovus  Implementation System, and Tempus  Timing Signoff Solution have a lot of shared functionality, but in the past, the separate legacy user interfaces (UIs) created a lot of differences.

A new common user interface that the Genus solution shares with the Innovus and Tempus solutions streamlines flow development and simplifies usability across the complete Cadence digital flow. The Stylus Common UI provides a next-generation synthesis-to-signoff flow with unified database access, MMMC timing configuration and reporting, and low-power design initialization.

This webinar answers the following questions:

• What is the Stylus Common UI and why did Cadence develop it?
• How does someone invoke and use the Stylus Common UI?
• What are some of the important and useful features of the Stylus Common UI?
• What are key ways the Stylus Common UI is different from the Legacy UI?

If you want to learn more about Stylus UI in the context of Genus Synthesis Solution, refer to 45-minute recorded webinar on https://support.cadence.com (Cadence login required).

Video Title: Webinar: Genus Synthesis Solution—Introduction to the Stylus Common UI (Video)

Direct Link: https://support.cadence.com/apex/ArticleAttachmentPortal?id=a1O0V000009MoGIUA0&pageName=ArticleContent

Related Resources

If interested in the full course, including lab content, please contact your Cadence representative or email a request to training_enroll@cadence.com. You can also enroll in the course on http://learning.cadence.com.​

Enhance the Genus Synthesis experience with videos: Genus Synthesis Solution: Video Library

For any questions, general feedback, or future blog topic suggestions, please leave a comment. 

Joules RTL Power Solution provides a cockpit for RTL designers to explore and optimize the power efficiency of their designs. But this capability is now not just limited to RTL designers!! Yes, you as a synthesis designer too can use the power analysis capabilities of Joules from within Genus Synthesis Solution!!

But:

• How to do it?
• Is there any specific switch required?
• What is the flow/script when Joules is used from within Genus?
• Are all the Joules commands supported?

To answer to all these questions is just a click away in the form of video on “Genus-Joules Integration”; refer it on https://support.cadence.com (Cadence login required).

Video Title: Genus-Joules Integration (Video)

Direct Link: https://support.cadence.com/apex/ArticleAttachmentPortal?id=a1O0V0000091CnXUAU&pageName=ArticleContent

Related Resources

Enhance the Genus Synthesis experience with videos: Genus Synthesis Solution: Video Library

Enhance the Joules experience with videos: Joules RTL Power Solution: Video Library

For any questions, general feedback, or future blog topic suggestions, please leave a comment. 

A recap of the blogs published in the Library Characterization Tidbits blog series.(read more)

Read how the Cadence Liberate Characterization solution effectively enables you to characterize only the failed or new arcs of a standard cell.(read more)

Key Findings: Advantest, in mixed-signal SoC design, sees 50X speedup, 25 day test reduced to 12 hours, dramatic test coverage increase.

Trolling through the CDNLive archives, I discovered another gem. At the May 2013 CDNLive in Munich, Thomas Henkel and Henriette Ossoinig of Advantest presented a paper titled “Timing-accurate emulation of a mixed-signal SoC using Palladium XP”. Advantest makes advanced electronics test equipment. Among the semiconductor designs they create for these products is a test processor chip with over 100 million logic transistors, but also with lots of analog functions.They set out to find a way to speed up their full-chip simulations to a point where they could run the system software. To do that, they needed about a 50X speed-up. Well, they did it!

Figure 1: Advantest SoC Test Products

To skip the commentary, read Advantest's paper here. 

Problem Statement

Software is becoming a bigger part of just about every hardware product in every market today, and that includes the semiconductor test market. To achieve high product quality in the shortest amount of time, the hardware and software components need to be verified together as early in the design cycle as possible. However, the throughput of a typical software RTL simulation is not sufficient to run significant amounts of software on a design with hundreds of millions of transistors.  

Executing software on RTL models of the hardware means long runs  (“deep cycles”) that are a great fit for an emulator, but the mixed-signal content posed a new type of challenge for the Advantest team.  Emulators are designed to run digital logic. Analog is really outside of the expected use model. The Advantest team examined the pros and cons of various co-simulation and acceleration flows intended for mixed signal and did not feel that they could possibly get the performance they needed to have practical runtimes with software testbenches. They became determined to find a way to apply their Palladium XP platform to the problem.

Armed with the knowledge of the essential relationship between the analog operations and the logic and software operations, the team was able to craft models of the analog blocks using reduction techniques that accurately depicted the essence of the analog function required for hardware-software verification without the expense of a continuous time simulation engine.

The requirements boiled down to the following:

• Generation of digital signals with highly accurate and flexible timing

• Complete chip needs to run on Palladium XP platform

• Create high-resolution timing (100fs) with reasonable emulation performance, i.e. at least 50X faster than simulation on the fastest workstations

Solution Idea

The solution approach chosen was to simplify the functional model of the analog elements of the design down to generation of digital signal edges with high timing accuracy. The solution employed a fixed-frequency central clock that was used as a reference.Timing-critical analog signals used to produce accurately placed digital outputs were encoded into multi-bit representations that modeled the transition and timing behavior. A cell library was created that took the encoded signals and converted them to desired “regular signals”. 

Automation was added to the process by changing the netlisting to widen the analog signals according to user-specified schematic annotations. All of this was done in a fashion that is compatible with debugging in Cadence’s Simvision tool.  Details on all of these facets to follow.

The Timing Description Unit (TDU) Format

The innovative thinking that enabled the use of Palladium XP was the idea of combining a reference clock and quantized signal encoding to create offsets from the reference. The implementation of these ideas was done in a general manner so that different bit widths could easily be used to control the quantization accuracy.

Figure 2: Quantization method using signal encoding

Timed Cell Modeling

You might be thinking – timing and emulation, together..!?  Yes, and here’s a method to do it….

The engineering work in realizing the TDU idea involved the creation of a library of cells that could be used to compose the functions that convert the encoded signal into the “real signals” (timing-accurate digital output signals). Beyond some basic logic cells (e.g., INV, AND, OR, MUX, DFF, TFF, LATCH), some special cells such as window-latch, phase-detect, vernier-delay-line, and clock-generator were created. The converter functions were all composed from these basic cells. This approach ensured an easy path from design into emulation.

The solution was made parameterizable to handle varying needs for accuracy.  Single bit inputs need to be translated into transitions at offset zero or a high or low coding depending on the previous state.  Single bit outputs deliver the final state of the high-resolution output either at time zero, the next falling, or the next rising edge of the grid clock, selectable by parameter. Output transitions can optionally be filtered to conform to a configurable minimum pulse width.

Timed Cell Structure

There are four critical elements to the design of the conversion function blocks (time cells):

                Input conditioning – convert to zero-offset, optional glitch preservation, and multi-cycle path

                Transition sorting – sort transitions according to timing offset and specified precedence

                Function – for each input transition, create appropriate output transition

                Output filtering – Capability to optionally remove multiple transitions, zero-width, pulses, etc.

Timed Cell Caveat

All of the cells are combinational and deliver a result in the same cycle of an input transition. This holds for storage elements as well. For example a DFF will have a feedback to hold its state. Because feedback creates combinational loops, the loops need a designation to be broken (using a brk input conditioning function in this case – more on this later). This creates an additional requirement for flip-flop clock signals to be restricted to two edges per reference clock cycle.

Note that without minimum width filtering, the number of output transitions of logic gates is the sum of all input transitions (potentially lots of switching activity). Also note that the delay cell has the effect of doubling the number of output transitions per input transition.

Figure 3: Edge doubling will increase switching during execution

SimVision Debug Support

The debug process was set up to revolve around VCD file processing and directed and viewed within the SimVision debug tool. In order to understand what is going on from a functional standpoint, the raw simulation output processes the encoded signals so that they appear as high-precision timing signals in the waveform viewer. The flow is shown in the figure below.

Figure 4: Waveform post-processing flow

The result is the flow is a functional debug view that includes association across representations of the design and testbench, including those high-precision timing signals.

Figure 5: Simvision debug window setup

Overview of the Design Under Verification (DUV)

Verification has to prove that analog design works correctly together with the digital part. The critical elements to verify include:

• Programmable delay lines move data edges with sub-ps resolution

• PLL generates clocks with wide range of programmable frequency

• High-speed data stream at output of analog is correct

These goals can be achieved only if parts of the analog design are represented with fine resolution timing.

Figure 6: Mixed-signal design partitioning for verification

How to Get to a Verilog Model of the Analog Design

There was an existing Verilog cell library with basic building blocks that included:

- Gates, flip-flops, muxes, latches

- Behavioral models of programmable delay elements, PLL, loop filter, phase detector

With a traditional simulation approach, a cell-based netlist of the analog schematic is created. This netlist is integrated with the Verilog description of the digital design and can be simulated with a normal workstation. To use Palladium simulation, the (non-synthesizable) portions of the analog design that require fine resolution timing have to be replaced by digital timing representation. This modeling task is completed by using a combination of the existing Verilog cell library and the newly developed timed cells.

Loop Breaking

One of the chief characteristics of the timed cells is that they contain only combinational cells that propagate logic from inputs to outputs. Any feedback from a cell’s transitive fanout back to an input creates a combinational loop that must be broken to reach a steady state. Although the Palladium XP loop breaking algorithm works correctly, the timed cells provided a unique challenge that led to unpredictable results.  Thus, a process was developed to ensure predictable loop breaking behavior. The user input to the process was to provide a property at the loop origin that the netlister recognized and translated to the appropriate loop breaking directives.

Augmented Netlisting

Ease of use and flow automation were two primary considerations in creating a solution that could be deployed more broadly. That made creating a one-step netlisting process a high-value item. The signal point annotation and automatic hierarchy expansion of the “digital timing” parameter helped achieve that goal. The netlister was enriched to identify the key schematic annotations at any point in the hierarchy, including bit and bus signals.

Consistency checking and annotation reporting created a log useful in debugging and evolving the solution.

Wrapper Cell Modeling and Verification

The netlister generates a list of schematic instances at the designated “netlister stop level” for each instance the requires a Verilog model with fine resolution timing. For the design in this paper there were 160 such instances.

The library of timed cells was created; these cells were actually “wrapper” cells comprised of the primitives for timed cell modeling described above. A new verification flow was created that used the behavior of the primitive cells as a reference for the expected behavior of the composed cells. The testing of the composed cells included had the timing width parameter set to 1 to enable direct comparison to the primitive cells. The Cadence Incisive Enterprise Simullator tool was successfully employed to perform assertion-based verification of the composed cells versus the existing primitive cells.

Mapping and Long Paths

Initial experiments showed that inclusion of the fine resolution timed cells into the digital emulation environment would about double the required capacity per run. As previously pointed out, the timed cells having only combinational forward paths creates a loop issue. This fact also had the result of creating some such paths that were more than 5,000 steps of logic. A timed cell optimization process helped to solve this problem. The basic idea was to break the path up by adding flip-flops in strategic locations to reduce combinational path length. The reason that this is important is that the maximum achievable emulation speed is related to combinational path length.

Results

Once the flow was in place, and some realistic test cases were run through it, some further performance tuning opportunities were discovered to additionally reduce runtimes (e.g., Palladium XP tbrun mode was used to gain speed). The reference used for overall speed gains on this solution was versus a purely software-based solution on the highest performance workstation available.

The findings of the performance comparison were startlingly good:

• On Palladium XP, the simulation speed is 50X faster than on Advantest’s fastest workstation

• Software simulation running 25 days can now be run in 12 hours -> realistic runtime enables long-running tests that were not feasible before

• Now have 500 tests that execute once in more than 48 hours

• They can be run much more frequently using randomization and this will increase test coverage dramatically

Steve Carlson

The complexity and size of mixed-signal designs in wireless, power management, automotive, and other fast growing applications requires continued advancements in a mixed-signal verification methodology. An SoC, in these fast growing applications, incorporates a large number of analog and mixed-signal (AMS) blocks/IPs, some acquired from IP providers, some designed, often concurrently. AMS IP must be verified independently, but this is not sufficient to ensure an SoC will function properly and all scenarios of interaction among many different AMS IP blocks at full chip / SoC level must be verified thoroughly. To reduce an overall verification cycle, AMS IP and SoC verification teams must work in parallel from early stages of the design. Easier said than done! We will outline a methodology than can help.

AMS designers verify their IP meets required specifications by running a testbench they develop for standalone / out of-context verification. Typically, an AMS IP as analog-centric, hierarchal design in schematic, composed of blocks represented by transistor, HDL and behavioral description verified in Virtuoso® Analog Design Environment (ADE) using Spectre AMS Designer simulation. An SoC verification team typically uses UVM SystemVerilog testbech at full chip level where the AMS IP is represented with a simple digital or real number model running Xcelium /DMS simulation from the command line.

Ideally, AMS designers should also verify AMS IP function properly in the context of full-chip integration, but reproducing an often complex UVM SystemVerilog testbench and bringing over top-level design description to an analog-centric environment is not a simple task.

Last year, Cadence partnered with Infineon on a project with a goal to automate the reuse of a top-level testbench in AMS verification. The automation enabled AMS verification engineers to automatically configure setup for verification runs by assembling all necessary options and files from the AMS IP Virtuoso GUI and digital SoC top-level command line configurations. The benefits of this method were:

• AMS verification engineers did not need to re-create complex stimuli representing interaction of their IP at the top level
• Top-level verification stays external to the AMS IP verification environment and continues to be managed by the SoC verification team, but can be reused by the AMS IP team without manual overhead
• AMS IP is verified in-context and any inconsistencies are detected earlier in the verification process
• Improved productivity and overall verification time

For more details, please see Infineon’s CDNLlive presentation.

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?

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)

Since the release of the Automated Device Placement and Routing solution last year, we have continued to improve and build upon it. In this blog, I’ll talk about the latest addition—the Auto Device Array form—how this is an integral piece of the new Automated Device Placement and Routing solution.(read more)

Here is another blog in the multi-part series that aims at providing in-depth details of electromagnetic analysis in the Virtuoso RF solution. Read to learn about the nuances of port setup for electromagnetic analysis.(read more)

Do you want to create designs that are correct by construction? Read along this blog to understand how you can achieve this by using Width Spacing Patterns (WSPs) in your designs. WSPs, are track lines that provide guidance for quickly creating wires. Defining WSPs that capture the width-dependent spacing rules, and snapping the pathSegs of a wire to them, ensures that the wires meet width-dependent spacing rules.(read more)

If you have one of those Die layouts, which doesn’t have bumps, but rather uses pad shapes and labels to identify I/O locations, then you might be feeling a bit left out of all of this jazz and tango. Hence, today, I am writing to tell you that, fear not, we have a solution for your Die as well.(read more)

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

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ڈونالڈ ٹرمپ کی صلاح کے بعد نیویارک مں جراثیم کو مارنے والی اشیا کے پینے کے 30 سے یادہ معاملے سامنے آئے ہیں۔ شہر کے ہیلتھ ڈپارٹمینٹ کے تحت آنے والے (Poison Control Center) کے پاس اس طرح کے معاملات کی گزشتہ 18گھنٹوں میں 30 سے زیادہ کالس آئی ہیں۔ حالانکہ ان میں سے کسی بھی نہ ےو موت ہوئی ہ ہی کسی کو اسپتال(hospital admit) میں داخل کرنے کی ضرورت پڑی ہے۔ ان میں سے زیادہ تر معاملے گھر کی صاف۔صفائی کیلئے استعمال کئے جانے کیلئے استعمال کئے جانے والا (lizol) کے استعمال سے جڑے ہیں۔

کمپنی نے لوگوں سے کہا، " مہربانی کرکے انہیں نہ پئیں، یہ صحت کیلئے کافی خطرناک ہیں، ان سے موت بھی ہوسکتی ہے"۔ ریکٹ بینکسر (Reckitt Benckiser-RBGLY) نے کہا کہ امریکی صدر ڈونالڈ ٹرمپ کے بیان کے بعد سوشل میڈیا پر گمراہ کن خبروں کو پھیلایا جارہا ہے۔ یہ سبھی غلط ہے۔

آج بیکہم اور وکٹوریہ دنیا کے سب سے طاقت ور جوڑوں میں سے ہیں ، جس کی بنیاد 23 سال سے پیار پر ہی ہے ۔ دونوں چار بچوں کے والدین ہیں ۔

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છોટા ઉદેપુરઃ છોટા ઉદેપુરના ડીવાયએસપી બુળરાજ.એ. વાળા દ્વારા આજે કચેરીમાં જ આપઘાતનો પ્રયાસ કરાતા ચકચાર મચી જવા પામી છે. DYSP વાળાએ સર્વિસ રિવોલ્વર વડે જાતે ગોળી મારી આપઘાતનો પ્રયાસ કર્યો હતો. જેથી તેમને સારવાર માટે તાત્કાલીક હોસ્પિટલ ખસેડાયા છે. જ્યાં તેમની હાલત ગંભીર હોવાનું જાણવા મળ્યું છે. ક્યા કારણોસર તેમણે આ પગલુ ભર્યું છે આ અંગે પોલીસે તપાસ હાથ ધરી છે.છોટા ઉદેપુર SP સહિતના અધિકારીઓ ઘટના સ્થળે પહોંચ્યા છે.

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ریلائنس جیو میں یہ تیسری ہائی پروفائل سرمایہ کاری ہے۔ فیس بک نے جیو میں 9.9 فیصد حصے داری 43،534 کروڑ روپئے میں اور سلور لیک نے 555 کروڑ میں 1.55فیصد حصے داری کی سرمایہ کاری کی۔ اس ہفتے کی شروعات میں Jio میں سلور لیک کے ذریعے کی گئی سرمایہ کاری بھی فیس بک ڈیل کے پریمیم جیسی تھی۔ تین ہفتوں کے اندر جیو پلیٹ فارم نے ٹیکنا لوجی سرمایہ کاروں سے 60،596.37 کروڑ روپئے جٹائے ہیں۔

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