It’s been quite a long 5-year journey building and deploying Performance Analysis, Verification, and Debug capabilities for Arm-based SoCs. We worked with some of the smartest engineers on the planet. First with the engineers at Arm, with whom we...(read more)

It’s always good to hear what real users think of products. Here is a very detailed review (~4000 words) by an Anonymous user, nick named Ant-Man (from the movie). Overall it’s a very strong endorsement of Perspec, and summarize...(read more)

CDNLive is a user conference, and verification is one of the largest categories of content with multiple tracks covering multiple days. Portable stimulus is one of the hottest new areas in verification, and continues to be popular in all venues. At l...(read more)

Cadence ® Spectre ® AMS Designer is a high-performance mixed-signal simulation system. The ability to use multiple engines, and drive from a variety of platforms enables you to "rev...

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

The 2019 HF1 production release for Clarity, Celsius, and Sigrity Tools is now available for download at Cadence Downloads . SIGRITY2019 HF1 For information about supported platforms, compatibility...

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

Do you have a set of Bluetooth earbuds yet? If not, you will. The iPhone was the first to kill the ubiquitous 3.5mm headphone jack, but many other manufacturers have quietly followed. Of course,...

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

You must deal with many reports in your daily life – for your health, financial accounts, credit, your child’s academic records, and the count goes on. Ever noticed that these reports contain many details, most of which you don’t wa...(read more)

With ECAD-MCAD Library Creator, you can easily create footprints for your parts using thousands of ready-to-use templates that are provided with the tool.(read more)

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)

In my previous blog, I talked about creating a footprint using an existing template in Allegro ECAD-MCAD Library Creator and explained how easily you can access an existing template and create a package from it by just clicking a button. In this blog...(read more)

I noticed some very interesting news last week, widely reported in the technical press, and you can find the source press release here. In a nutshell, the Embedded Microprocessor Benchmark Consortium (EEMBC) has formed a group to look at benchmarks for ultra low power microcontrollers. Initially chaired by Horst Diewald, chief architect of MSP430^TM microcontrollers at Texas Instruments, the group's line-up is an impressive "who's who" of the microcontroller space, including Analog Devices, ARM, Atmel, Cypress, Energy Micro, Freescale, Fujitsu, Microchip, Renesas, Silicon Labs, STMicro, and TI.

As the press release explains, unlike usual processor benchmark suites which focus on performance, the ULP benchmark will focus on measuring the energy consumed by microcontrollers running various computational workloads over an extended time period. The benchmarking methodology will allow the microcontrollers to enter into their idle or sleep modes during the majority of time when they are not executing code, thereby simulating a real-world environment where products must support battery life measured in months, years, and even decades.

Processor performance benchmarks seem to be as widely criticized as EPA fuel consumption figures for cars - and the criticism is somewhat related. There is a suspicion that manufacturers can tune the performance for better test results, rather than better real-world performance. On the face of it, the task to produce meaningful ultra low power benchmarks seems even more fraught with difficulties. For a start, there is a vast range of possible energy profiles - different ways that computing is spread over time - and a plethora of low power design techniques available to optimize the system for the set of profiles that particular embedded system is likely to experience. Furthermore, you could argue that, compared with performance in a computer system, energy consumption in an ultra low power embedded system has less to do with the controller itself and more to do with other parts of the system like the memories and mixed-signal real-world interfaces.

EEMBC cites that common methods to gauge energy efficiency are lacking in growth applications such as portable medical devices, security systems, building automation, smart metering, and also applications using energy harvesting devices. At Cadence, we are seeing huge growth in these areas which, along with intelligence being introduced into all kinds of previously "dumb" appliances, is becoming known as the "Internet of Things." Despite the difficulties, with which the parties involved are all deeply familiar, I applaud this initiative. While it may be difficult to get to apples-to-apples comparisons for energy consumption in these applications, most of the time today we don't even know where the grocery store is. If the EEMBC effort at least gets us to the produce department, we're going to be better off.

Pete Hardee 

If you weren't able to attend the 2013 DVCon, you missed out on a great IEEE 1801/UPF tutorial delivered by members of the IEEE committee. Accellera had the event recorded and that recording is now posted on the Accellera.org website. Regardless of your work so far with low power design and verification, you need to watch this video.

Power management is becoming ubiquitous in our world. The popular aspect is that reduced power is good for the evironment and that is true. But for those teams that have been building chips around the 40nm node and below, there is another truth. Power management is required simply to get working silicon in many cases. As the industry expands the number of designs with power management and forges deeper into advanced nodes, we steadily identify improvements to the power format descriptions. The most recent set of imporvements to the IEEE 1801 standard are now available in the 2013 version of that standard.

To help bring the standard to life, five representatives from the IEEE joined to deliver a tutorial at DVCon in 2013. Qi Wang (Cadence), Erich Marschner (Mentor), Jeffrey Lee (Synopsys), John Biggs (ARM), and Sushma Honnavarra-Prasad (Broadcom) each contributed to the tutorial. It started with a review of the UPF basics that led to the IEEE 1801 standard delivered by the EDA companies. The IEEE 1801 users then presented tutorial content on how to apply the standard. The session then concluded with a look forward to the IEEE 1801-2013 (UPF 2.1) standard. The standard was released two months after the DVCon tutorial and is available through the Accellera Get program.

So after the bowl games are over and you'vre returned through the woods and back over the river from Grandma's, grab a cup of hot cocoa and learn more about the power standards you may well be using in 2014.

Regards,

Adam "The Jouler" Sherer

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. 

Hello, I have a problem with a certain type of transistor,my hyrarchy has a lot components an sub components and visually inspecting them is very hard.

is there a way like in other cadence layout viewer tools , to enter the name of the component or a NET somewhere and it will focus on it visualy or give the hyrarchy path to it?

Thanks.

hi everyone, 

i'm trying to create a netlist for aging simulation. i would like to simulate how power, Gain and PAE (efficiency) are inlfuenced after 3 hours

i would be grateful if someone can correct my syntax in the netlist since i'm trying to make a sweep HB  simulation where the input power is the parameter.

i did it without any error for the sp (S parameters)  simulation.

you can see the images for both sp and hb simulation netlists. (from left to right: sp aging netlist; hb aging netlist)

i will be grateful if someone can provide me some syntax advices.

thanks,

best regards

Hi Guys,

Anyone know equivalent skill for create detail.

Eugene

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.

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?

Currently I tried this:

axlDBCreateShape(recPolyPlanes t "BOUNDARY/L02" netName sym1)

I get a atom error on car(sym1)

I can do this "static" using ETCH/L02 with out an issue, but I am trying to avoid doing an axlShapeChangeDynamicType().

Thanks,

Jerry

Hi all,

I am creating shapes on plane layers for a coupon and want to void them using axlShapeAutoVoid()

The shapes are attached to a symbol.

I've tried using axlShapeAutoVoid, but this only voids the pins, not the route keepouts created by nc_backdrill.

I also tried selecting the shape, individually, then running axlShapeAutoVoid. That was unsuccessful, also.

planeShapes is a list of shapes I created. The code for voiding:

;run backdrill to get route keepouts
axlShell("setwindow pcb;backdrill setup ;setwindow form.nc_backdrill;FORM nc_backdrill apply ;FORM nc_backdrill close")

foreach(sHape planeShapes
axlShapeAutoVoid(car(sHape))
)

Hi guys,

eDave,

I need to call (replay) a skill to combine some skills to ONE UI for more convenience and using as more easier.

Please help me to find the command to execute this.(code for example as more good)

HT,

Hi, I'm trying to create a circle from a pin with 10 mil air gap and at 45 degree rotation. The problem that im facing is that, I'm unable to get the bBox upper left coordinates. Because I want my circle to be placed from that coordinate with a 10 mil air gap. And the pins are "regular" and are placed on "Etch/Top" Layer. Kindly help me in solving this issue.

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

This is the 21st installment of The Rationalist, my column for the Times of India.

When all political parties agree on something, you know you might have a problem. Giriraj Singh, a minister in Narendra Modi’s new cabinet, tweeted this week that our population control law should become a “movement.” This is something that would find bipartisan support – we are taught from school onwards that India’s population is a big problem, and we need to control it.

This is wrong. Contrary to popular belief, our population is not a problem. It is our greatest strength.

The notion that we should worry about a growing population is an intuitive one. The world has limited resources. People keep increasing. Something’s gotta give.

Robert Malthus made just this point in his 1798 book, An Essay on the Principle of Population. He was worried that our population would grow exponentially while resources would grow arithmetically. As more people entered the workforce, wages would fall and goods would become scarce. Calamity was inevitable.

Malthus’s rationale was so influential that this mode of thinking was soon called ‘Malthusian.’ (It is a pejorative today.) A 20th-century follower of his, Harrison Brown, came up with one of my favourite images on this subject, arguing that a growing population would lead to the earth being “covered completely and to a considerable depth with a writhing mass of human beings, much as a dead cow is covered with a pulsating mass of maggots.”

Another Malthusian, Paul Ehrlich, published a book called The Population Bomb in 1968, which began with the stirring lines, “The battle to feed all of humanity is over. In the 1970s hundreds of millions of people will starve to death in spite of any crash programs embarked upon now.” Ehrlich was, as you’d guess, a big supporter of India’s coercive family planning programs. ““I don’t see,” he wrote, “how India could possibly feed two hundred million more people by 1980.”

None of these fears have come true. A 2007 study by Nicholas Eberstadt called ‘Too Many People?’ found no correlation between population density and poverty. The greater the density of people, the more you’d expect them to fight for resources – and yet, Monaco, which has 40 times the population density of Bangladesh, is doing well for itself. So is Bahrain, which has three times the population density of India.

Not only does population not cause poverty, it makes us more prosperous. The economist Julian Simon pointed out in a 1981 book that through history, whenever there has been a spurt in population, it has coincided with a spurt in productivity. Such as, for example, between Malthus’s time and now. There were around a billion people on earth in 1798, and there are around 7.7 billion today. As you read these words, consider that you are better off than the richest person on the planet then.

Why is this? The answer lies in the title of Simon’s book: The Ultimate Resource. When we speak of resources, we forget that human beings are the finest resource of all. There is no limit to our ingenuity. And we interact with each other in positive-sum ways – every voluntary interactions leaves both people better off, and the amount of value in the world goes up. This is why we want to be part of economic networks that are as large, and as dense, as possible. This is why most people migrate to cities rather than away from them – and why cities are so much richer than towns or villages.

If Malthusians were right, essential commodities like wheat, maize and rice would become relatively scarcer over time, and thus more expensive – but they have actually become much cheaper in real terms. This is thanks to the productivity and creativity of humans, who, in Eberstadt’s words, are “in practice always renewable and in theory entirely inexhaustible.”

The error made by Malthus, Brown and Ehrlich is the same error that our politicians make today, and not just in the context of population: zero-sum thinking. If our population grows and resources stays the same, of course there will be scarcity. But this is never the case. All we need to do to learn this lesson is look at our cities!

This mistaken thinking has had savage humanitarian consequences in India. Think of the unborn millions over the decades because of our brutal family planning policies. How many Tendulkars, Rahmans and Satyajit Rays have we lost? Think of the immoral coercion still carried out on poor people across the country. And finally, think of the condescension of our politicians, asserting that people are India’s problem – but always other people, never themselves.

This arrogance is India’s greatest problem, not our people.

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

Hi supporters,

I got the following error while I run simulation with gate netlist using Cadence Incisive (v15.20):

----

ncsim(64): 15.20-s076: (c) Copyright 1995-2019 Cadence Design Systems, Inc.
ncsim: *E,DLOALB: Design library 'tcbnxxx' not defined while reading module tcbnxxx.MAOxxx:bv (VST).
ncsim: *F,NOSIMU: Errors initializing simulation 'alu_tb' 

----

xxx: standard library name.

My netlist design uses a cell "MAOxxx". I already included the library behavior model to compile using ncverilog, there is no error while compiling. But when I run with ncsim to execute the test, I got above error.

I tried to run with other vendors such as VCS or MTI, they worked.

Please help to understand the error.

Thanks.

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?

Hello folks,

Greetings.

One of my customer claims that he is using Cadence IES version 18.09.011 with Vivado 2019.2. The version of IES that we officially support with Vivado 2019.2 is 15.20.073. Though the tool is forward compatible, I am not sure what are the versions of IES that are released after 15.20.073. Could you please give me a list of the versions of Cadence IES released after 15.20.073 and which is the latest version as of now ?

Best regards,

Chinmay

Specman *search* command allows searching in all loaded modules, but only for a string.

Is there a way to search for a regexp or glob?

Alternatively, is there a way to simply get a list of all loaded files somehow? Then I could use either the "shell" command, or real shell together with grep.

Thanks

When I run simulation with irun, it may use may license features. How can I know which feature(s) a product use? I get below message in cdnshelp:

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

Which Products Are in the License File?

One Cadence product can require more than one license (FEATURE). The product to feature mapping in the license file lists the licenses each product needs.

For example, if the license file lists these features for the NC-VHDL Simulator:

Product Name: Cadence(R) NC-VHDL Simulator
#
Type: Floating Exp Date: 31-jul-2006 Qty: 1
#
Feature: NC_VHDL_Simulator [Version: 9999.999]
#
Feature: Affirma_sim_analysis_env [Version: 9999.999]

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

But, in my license file, I can't find such info. There is only "FEATURE" lines in my license file. How can I get product to feature mapping info?

Thanks!

Molding caps aren’t something we talk about too frequently around here. We all know they exist, and they serve an important purpose of protecting the delicate die from potentially harsh environmental conditions. They impact how well heat can be...(read more)

Hi everyone! I'm working on a small battery powered PCB which will fit inside a small plastic "hockey puck" container. A number of these "pucks" will be sold together with a "charging doc" which will store and charge the pucks when not in use.

I'm trying to work out the best way to charge the battery. I'm thinking of having metal "pads" on the rr.com puck that pass through the puck's plastic shell and then make contact with the PCB on the inside, and having a similar system on the charging dock. I'm thinking of having SMD "contact sprints" mounted to the underside of the PCB and have these mate against metal pins that protrude through the puck, but it's the later of which I'm struggling to find. For a visual, think about "restaurant pagers" and how they charge.

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.

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.

Please include a brief summary of how to use it.

Hi everybody,

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

Hilmar

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

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;
};
};

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,

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

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)

Key Findings: Many more design teams will be reaching the mixed-signal methodology tipping point in 2015. That means you need to have a (verification) plan, and measure and execute against it.

As 2014 draws to a close, it is time to look ahead to the coming years and make a plan. While the macro view of the chip design world shows that is has been a mixed-signal world for a long time, it is has been primarily the digital teams that have rapidly evolved design and verification practices over the past decade. Well, I claim that is about to change. 2015 will be a watershed year for many more design teams because of the following factors:

• 85% of designs are mixed signal, and it is going to stay that way (there is no turning back)
• Advanced node drives new techniques, but they will be applied on all nodes
• Equilibrium of mixed-signal designs being challenged, complexity raises risk level
• Tipping point signs are evident and pervasive, things are going to change
• The convergence of “big A” and “big D” demands true mixed-signal practices

Reason 1: Mixed-signal is dominant

To begin the examination of what is going to change and why, let’s start with what is not changing. IBS reports that mixed signal accounts for over 85% of chip design starts in 2014, and that percentage will rise, and hold steady at 85% in the coming years. It is a mixed-signal world and there is no turning back!

Figure 1. IBS: Mixed-signal design starts as percent of total

The foundational nature of mixed-signal designs in the semiconductor industry is well established. The reason it is exciting is that a stable foundation provides a platform for driving change. (It’s hard to drive on crumbling infrastructure.  If you’re from California, you know what I mean, between the potholes on the highways and the earthquakes and everything.)

Reason 2: Innovation in many directions, mostly mixed-signal applications

While the challenges being felt at the advanced nodes, such as double patterning and adoption of FinFET devices, have slowed some from following onto to nodes past 28nm, innovation has just turned in different directions. Applications for Internet of Things, automotive, and medical all have strong mixed-signal elements in their semiconductor content value proposition. What is critical to recognize is that many of the design techniques that were initially driven by advanced-node programs have merit across the spectrum of active semiconductor process technologies. For example, digitally controlled, calibrated, and compensated analog IP, along with power-reducing mutli-supply domains, power shut-off, and state retention are being applied in many programs on “legacy” nodes.

Another graph from IBS shows that the design starts at 45nm and below will continue to grow at a healthy pace.  The data also shows that nodes from 65nm and larger will continue to comprise a strong majority of the overall starts. 

Figure 2.  IBS: Design starts per process node

TSMC made a comprehensive announcement in September related to “wearables” and the Internet of Things. From their press release:

TSMC’s ultra-low power process lineup expands from the existing 0.18-micron extremely low leakage (0.18eLL) and 90-nanometer ultra low leakage (90uLL) nodes, and 16-nanometer FinFET technology, to new offerings of 55-nanometer ultra-low power (55ULP), 40ULP and 28ULP, which support processing speeds of up to 1.2GHz. The wide spectrum of ultra-low power processes from 0.18-micron to 16-nanometer FinFET is ideally suited for a variety of smart and power-efficient applications in the IoT and wearable device markets. Radio frequency and embedded Flash memory capabilities are also available in 0.18um to 40nm ultra-low power technologies, enabling system level integration for smaller form factors as well as facilitating wireless connections among IoT products.

Compared with their previous low-power generations, TSMC’s ultra-low power processes can further reduce operating voltages by 20% to 30% to lower both active power and standby power consumption and enable significant increases in battery life—by 2X to 10X—when much smaller batteries are demanded in IoT/wearable applications.

The focus on power is quite evident and this means that all of the power management and reduction techniques used in advanced node designs will be coming to legacy nodes soon.

Integration and miniaturization are being pursued from the system-level in, as well as from the process side. Techniques for power reduction and system energy efficiency are central to innovations under way.  For mixed-signal program teams, this means there is an added dimension of complexity in the verification task. If this dimension is not methodologically addressed, the level of risk adds a new dimension as well.

Reason 3: Trends are pushing the limits of established design practices

Risk is the bane of every engineer, but without risk there is no progress. And, sometimes the amount of risk is not something that can be controlled. Figure 3 shows some of the forces at work that cause design teams to undertake more risk than they would ideally like. With price and form factor as primary value elements in many growing markets, integration of analog front-end (AFE) with digital processing is becoming commonplace.  

Figure 3.  Trends pushing mixed-signal out of equilibrium

The move to the sweet spot of manufacturing at 28nm enables more integration, while providing excellent power and performance parameters with the best cost per transistor. Variation becomes great and harder to control. For analog design, this means more digital assistance for calibration and compensation. For greatest flexibility and resiliency, many will opt for embedding a microcontroller to perform the analog control functions in software. Finally, the first wave of leaders have already crossed the methodology bridge into true mixed-signal design and verification; those who do not follow are destined to fall farther behind.

Reason 4: The tipping point accelerants are catching fire

The factors cited in Reason 3 all have a technical grounding that serves to create pain in the chip-development process. The more factors that are present, the harder it is to ignore the pain and get the treatment relief  afforded by adopting known best practices for truly mixed-signal design (versus divide and conquer along analog and digital lines design).

In the past design performance was measured in MHz with simple static timing and power analysis. Design flows were conveniently partitioned, literally and figuratively, along analog and digital boundaries. Today, however, there are gigahertz digital signals that interact at the package and board level in analog-like ways. New, dynamic power analysis methods enabled by advanced library characterization must be melded into new design flows. These flows comprehend the growing amount of feedback between analog and digital functions that are becoming so interlocked as to be inseparable. This interlock necessitates design flows that include metrics-driven and software-driven testbenches, cross fabric analysis, electrically aware design, and database interoperability across analog and digital design environments.

Figure 4.  Tipping point indicators

Energy efficiency is a universal driver at this point.  Be it cost of ownership in the data center or battery life in a cell phone or wearable device, using less power creates more value in end products. However, layering multiple energy management and optimization techniques on top of complex mixed-signal designs adds yet more complexity demanding adoption of “modern” mixed-signal design practices.

Reason 5: Convergence of analog and digital design

Divide and conquer is always a powerful tool for complexity management.  However, as the number of interactions across the divide increase, the sub-optimality of those frontiers becomes more evident. Convergence is the name of the game.  Just as analog and digital elements of chips are converging, so will the industry practices associated with dealing with the converged world.

Figure 5. Convergence drivers

Truly mixed-signal design is a discipline that unites the analog and digital domains. That means that there is a common/shared data set (versus forcing a single cockpit or user model on everyone). 

In verification the modern saying is “start with the end in mind”. That means creating a formal approach to the plan of what will be test, how it will be tested, and metrics for success of the tests. Organizing the mechanics of testbench development using the Unified Verification Methodology (UVM) has proven benefits. The mixed-signal elements of SoC verification are not exempted from those benefits.

Competition is growing more fierce in the world for semiconductor design teams. Not being equipped with the best-known practices creates a competitive deficit that is hard to overcome with just hard work. As the landscape of IC content drives to a more energy-efficient mixed-signal nature, the mounting risk posed by old methodologies may cause causalities in the coming year. Better to move forward with haste and create a position of strength from which differentiation and excellence in execution can be forged.

Summary

2015 is going to be a banner year for mixed-signal design and verification methodologies. Those that have forged ahead are in a position of execution advantage. Those that have not will be scrambling to catch up, but with the benefits of following a path that has been proven by many market leaders.

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

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

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

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

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

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

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

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

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

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

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

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

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

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۔

લોકડાઉનમાં સામેની અગાશીમાં ઊભેલી યુવતીથી થયો પ્રેમ, દિલની વાત કહેવા કર્યો આ જુગાડ

Relianceની અન્ય સબ્સિડિયરી કંપનીઓના શૅરોમાં પણ જોરદાર તેજી જોવા મળી

મહિન્દ્રા ગ્રૂપના ચેરમેન આનંદ મહિન્દ્રાએ બુધવારે રિલાયન્સ ઇન્ડસ્ટ્રીઝ લિમિટેડના ચેરમેન મુકેશ અંબાણીની પ્રશંસા કરતા કહ્યું કે Facebook અને Jio ડીલ ફક્ત બે દેશો માટે નહીં પણ ભારતની અર્થવ્યવસ્થા માટે પણ સારી છે