All engineers can enhance their mixed-signal low-power structural verification productivity by learning while doing with a PIEA RAK (Power Intent Export Assistant Rapid Adoption Kit). They can verify the mixed-signal chip by a generating macromodel for their analog block automatically, and run it through Conformal Low Power (CLP) to perform a low power structural check.  

The power structure integrity of a mixed-signal, low-power block is verified via Conformal Low Power integrated into the Virtuoso Schematic Editor Power Intent Export Assistant (VSE-PIEA). Here is the flow.

Applying the flow iteratively from lower to higher levels can verify the power structure.

Cadence customers can learn more in a Rapid Adoption Kit (RAK) titled IC 6.1.5 Virtuoso Schematic Editor XL PIEA, Conformal Low Power: Mixed-Signal Low Power Structural Verification.

• To read the overview presentation, click on following link: PIEA Overview
• To download this PIEA RAK click on following link: PIEA RAK Download

The RAK includes Rapid Adoption Kit with demo design (instructions are provided on how to setup the user environment). It Introduces the Power Intent Export Assistant (PIEA) feature that has been implemented in the Virtuoso IC615 release.  The power intent extracted is then verified by calling Conformal Low Power (CLP) inside the Virtuoso environment.

• Last Update: 11/15/2012.
• Validated with IC 6.1.5 and CLP 11.1

The RAK uses a sample test case to go through PIEA + CLP flow as follows:

• Setup for PIEA
• Perform power intent extraction
• CPF Import: It is recommended to Import macro CPF, as oppose to designing CPF for sub-blocks. If you choose to import design CPF files please make sure the design CPF file has power domain information for all the top level boundary ports
• Generate macro CPF and design CPF
• Perform low power verification by running CLP

It is also recommended to go through older RAKs as prerequisites.

• Conformal Low Power, RTL Compiler and Incisive: Low Power Verification for Beginners
• Conformal Low Power: CPF Macro Models
• Conformal Low Power and RTL Compiler: Low Power Verification for Advanced Users

To access all these RAKs, visit our RAK Home Page to access Synthesis, Test and Verification flow

Note: To access above docs, use your Cadence credentials to logon to the Cadence Online Support (COS) web site. Cadence Online Support website https://support.cadence.com/ is your 24/7 partner for getting help and resolving issues related to Cadence software. If you are signed up for e-mail notifications, you can receive new solutions, Application Notes (Technical Papers), Videos, Manuals, and more.

You can send us your feedback by adding a comment below or using the feedback box on Cadence Online Support.

Sumeet Aggarwal

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 

There is no better way other than a self-help training kit -- (rapid adoption kit, or RAK) -- to demonstrate the Incisive Enterprise Simulator's IEEE 1801 / UPF low-power features and its usage. The features include:

• Unique SimVision debugging 
• Patent-pending power supply network visualization and debugging
• Tcl extensions for LP debugging
• Support for Liberty file power description
• Standby mode support
• Support for Verilog, VHDL, and mixed language
• Automatic understanding of complex feedthroughs
• Replay of initial blocks
• ‘x' corruption for integers and enumerated types
• Automatic understanding of loop variables
• Automatic support for analog interconnections

Mickey Rodriguez, AVS Staff Solutions Engineer has developed a low power UPF-based RAK, which is now available on Cadence Online Support for you to download.

• This rapid adoption kit illustrates Incisive Enterprise Simulator (IES) support for the IEEE 1801 power intent standard. 

Patent-Pending Power Supply Network Browser. (Only available with the LP option to IES)

• In addition to an overview of IES features, SimVision and Tcl debug features, a lab is provided to give the user an opportunity to try these out.

The complete RAK and associated overview presentation can be downloaded from our SoC and Functional Verification RAK page:

We are covering the following technologies through our RAKs at this moment:

Synthesis, Test and Verification flow
Encounter Digital Implementation (EDI) System and Sign-off Flow
Virtuoso Custom IC and Sign-off Flow
Silicon-Package-Board Design
Verification IP
SOC and IP level Functional Verification
System level verification and validation with Palladium XP

Please visit https://support.cadence.com/raks to download your copy of RAK.

We will continue to provide self-help content on Cadence Online Support, your 24/7 partner for learning more about Cadence tools, technologies, and methodologies as well as getting help in resolving issues related to Cadence software. If you are signed up for e-mail notifications, you're likely to notice new solutions, application notes (technical papers), videos, manuals, etc.

Note: To access the above documents, click a link and use your Cadence credentials to log on to the Cadence Online Support https://support.cadence.com/ website.

Happy Learning!

Sumeet Aggarwal and Adam Sherer

Hello,

Would anyone know how to setup a PSS or QPSS simulation with 25% dutycycle clock sources or if such a thing is possible with QPSS.

Fig1 (below) is a snapshot of the circuit I am trying to characterize. This has 4 clock ports each with 25%duty cycle in the ON state. Fig2 below shows two of these clocks.

Each path in the circuit consists of two switches with a low pass RC sandwiched in between. The Input is a 50Ohm port sine wave and the output is a 1K resistor. The output nets of all paths are connected together.

I am trying to determine the swept frequency response from input to output (voltage) when the input is from 500Mhz to  510MHz. The Period (T=1/Fp) of each of the pulses is such that Fp=500MHz. The first pulse source has a delay=0, second has delay=T/4, third delay=2T/4, etc...

I am currently getting it working and seeing the correct result (bandpass response) with Transient but the problem is doing a dft at 500MHz with 10KHz spacings needs at least 100us and takes up a lot of time and disk space.

Many Thanks,
Chris.

Fig1

Fig2

Hello

The document I referenced is https://filebox.ece.vt.edu/~symort/rfworkshop/Mixer_workshop_instruction.pdf. (This is cadence workshop document)

While following the pxf simulation in the above article, the results are different and I have a question.

My result picture is shown below.

<my result error>

<document result>

<my direct plot>

<document direct plot>

The difference with the documentation is that in the direct plot screen after the pxf simulation,

1.output harmonics-> input sideband

2.Frequency axis: out-> frequency axis: absin

3.The results for port0 (RF port) are also different (see photo below).

4.The frequency values in the box are different.

My screen shows 5G, 10G, 1K ~ 10M, but the document is the same as 1K ~ 10M.

Ask for a solution. Thank you.

Hello, i have built a matching network of 13dB gain and  NF as shown bellow step by step.(including all the plots and matlab )

its just not working at all,i am doing it exacly by the thoery

taking a point inside the circle-> converting its gamma to Z_source->converting gamma_s into gamma_L with the formulla bellow as shown in the matlab->converting the gamma_L into Z_L-> building the matching network for conjugate of Z_L and Z_c.Its just not working.

where did i got  wrong?

Thanks.

gamma_s=75.8966*exp(deg2rad(280.88)*i);
z_s=gamma2z(gamma_s,50);
s11=0.99875-0.03202*i
s12=721.33*10^(-6)+8.622*10^(-3)*i
s21=-188.37*10^(-3)+30.611*10^(-3)*i
s22=875.51*10^(-3)-100.72*10^(-3)*i
gamma_L=conj((s22+(s12*s21*gamma_s)/(1-s11*gamma_s)))
z_L=gamma2z(gamma_L,50)

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

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

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

Thanks.

Hi Guys,

Anyone know equivalent skill for create detail.

Eugene

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

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

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

Thanks,

Pradeep

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?

Hi , 

I am sharing with you some simple skill script that draw line in user layer :

axlCmdRegister("DrawLine" 'DrawLine)
procedure(DrawLine()
   layer_name = "substrate geometry/userlayer"
   mypopup = axlUIPopupDefine(nil '(
      ("Done" "axlDBTransactionCommit(mark), axlFinishEnterFun()")
      ("Oops" "axlDBTransactionOops(mark), when(zerop(--oopsNum)")
      ("Cancel" "axlDBTransactionRollback(mark), axlCancelEnterFun()")
      ("MENU_SEPARATOR", nil)))
   axlUIPopupSet( mypopup)
   ; Clear the dynamic buffer
   axlClearDynamics()

   if(axlLayerGet(layer_name) != nil then
      if(axlIsVisibleLayer(layer_name) == nil then
         axlVisibleLayer(layer_name,t)
         axlVisibleUpdate(t)
      );End if
   else
      if(axlLayerGet("substrate geometry") == nil then
         layer_name = "board geometry/userlayer"
         axlLayerCreateNonConductor(layer_name)
         axlVisibleLayer(layer_name,t)
         axlVisibleUpdate(t)
      else
         axlLayerCreateNonConductor(layer_name)
         axlVisibleLayer(layer_name,t)
         axlVisibleUpdate(t)
      );End if
   );End if

   ; Clear mypath to nil, then loop gathering user picks:
   mypath = nil
   mark = axlDBTransactionStart()
   flag = t
   allP = list(nil)
   seg1 = nil
   seg2 = nil
   while( (mypath = axlEnterPath(?lastPath mypath))
      if(flag == t then
         p = axlDBCreatePath(mypath, layer_name)
         seg1 = car(car(car(p))->segments)
         seg2 = car(cdr(car(car(p))->segments))
         path = axlPathStart( list(car(seg1->startEnd)) , 0)
         axlPathLine( path , 0 , car(cdr(seg1->startEnd)))
         if(seg2 then
            axlPathLine( path , 0 , car(cdr(seg2->startEnd)))
         );end if
         flag = nil
      else
         p = axlDBCreatePath(mypath, layer_name)
         seg1 = car(car(car(p))->segments)
         seg2 = car(cdr(car(car(p))->segments))
         axlPathLine( path , 0 , car(cdr(seg1->startEnd)))
         if(seg2 then
            axlPathLine( path , 0 , car(cdr(seg2->startEnd)))
         );end if
      );end if
      allP = cons(car(car(p)) allP)
   );Loop
   axlDBCreatePath(path, layer_name)
   forall( x allP axlDeleteObject(x))
);End procedure

Is anyone can help to understand why this script can work with 16.5/16.6/17.2 and doesn't work with 17.4 ?

To be more informative in 17.4 this script behaves differently , when i am trying to draw line i can't zoom in/out ,i can't use my shortcuts to snap it on segment/middle/edge , it's like it's waiting only for next X/Y user click , all other functions just disabled .

Thanks .

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))
)

I'm working on a circuit that requires the input voltage to be converted to a frequency, transmitted over an optical cable, and then converted back to a voltage. I am attempting to simulate this circuit using Eagle ngSpice simulations. The voltage to frequency converters that I am using are ADVFC32 and made by Analog Devices. However, I can't seem to find a SPICE model for this component. Analog Devices does not provide it on their website. Can anyone find a SPICE Model for this part? I'm new to working with electronics so any help/advice you can provide would be appreciated.

I have made a customized menu in PCB Editor which I now would like to fill with content.

First of all I would like to have commands to add (or delete) layers in the board. I have parameter files (.prm) that describes both the stackup and the artwork for 2, 4, 6 and 8 layers.

I guess I could record a script (macro) where I use the "Import Parameter file" dialogue but this will get windows flickering by etc. Can I do this with SKILL instead?

I realize that it is possible (somehow) to do a SKILL-script that completely builds up the stackup and artworks for boards with different number of layers but I then have to edit the SKILL everytime I need to change anything. My thinking is that it perhaps is easier just to call the prm-file, which is easy to modify from within Allegro without knowing anything about SKILL.

I'm also looking for a solution to remove some Subclasses, containing certain keywords with a SKILL script but since I'm completely new to SKILL I don't really know where to begin.

Any assistance would be much appreciated.

I am working on some SKILL scripts which are loaded by allegro.ilinit at startup.

If I edit my .il-files how do I get them updated in Allegro?

Right now I restart the program but there must be a simpler way.

A newbie question, I know...  

Hi,

I wanted to find the location of a pin in the design using skill program. pin_dbids = axlDBGetDesign()->pins, this gives me all the dbids of the pins that are present in my design. But when im entering that dbid, pad = axlDBGetPad("000001EA8FD8B9F8" "package geometry/assembly_top" "regular") it is throwing an error stating "This dbid is not user defined. Please enter the user defined". So please provide me a snippet so that I can get the exact pin location in the design using skill script.

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,

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 19th installment of The Rationalist, my column for the Times of India.

A friend of mine was very impressed by the interview Narendra Modi granted last week to Akshay Kumar. ‘Such a charming man, such great work ethic,’ he gushed. ‘He is the kind of uncle I would want my kids to have.’ And then, in the same breath, he asked, ‘How can such a good man be such a bad prime minister?”

I don’t want to be uncharitable and suggest that Modi’s image is entirely manufactured, so let’s take the interview at face value. Let’s also grant Modi his claims about the purity of his neeyat (intentions), and reframe the question this way: when it comes to public policy, why do good intentions often lead to bad outcomes? To attempt an answer, I’ll refer to a story a friend of mine, who knows Modi well, once told me about him. 

Modi was chilling with his friends at home more than a decade ago, and told them an incident from his childhood. His mother was ill once, and the young Narendra was tending to her. The heat was enervating, so the boy went to the switchboard to switch on the fan. But there was no electricity. My friend said that as he told this story, Modi’s eyes filled with tears. Even after all these years, he was moved by the memory.

My friend used this story to make the point that Modi’s vision of the world is experiential. If he experiences something, he understands it. When he became chief minister of Gujarat, he made it his stated mission to get reliable electricity to every part of Gujarat. No doubt this was shaped by the time he flicked a switch as a young boy and the fan did not budge. Similarly, he has given importance to things like roads and cleanliness, since he would have experienced the impact of those as a young man.

My term for him, inspired by Rajat Kapoor’s 2014 film, is ‘the ankhon dekhi prime minister’. At one level, this is a good thing. He sees a problem and works for the rest of his life to solve it. But what of things he cannot experience?

The economy is a complex beast, as is society itself, and beyond a certain level, you need to grasp abstract concepts to understand how the world works. You cannot experience them. For example, spontaneous order, or the idea that society and markets, like language, cannot be centrally directed or planned. Or the positive-sum nature of things, which is the engine of our prosperity: the idea that every transaction is a win-win game, and that for one person to win, another does not have to lose. Or, indeed, respect for individual rights and free speech.

One understands abstract concepts by reading about them, understanding them, applying them to the real world. Modi is not known to be a reader, and this is not his fault. Given his background, it is a near-miracle that he has made it this far. He wasn’t born into a home with a reading culture, and did not have either the resources or the time when he was young to devote to reading. The only way he could learn about the world, thus, was by experiencing it.

There are two lessons here, one for Modi himself and others in his position, and another for everyone.

The lesson in this for Modi is a lesson for anyone who rises to such an important position, even if he is the smartest person in the world. That lesson is to have humility about the bounds of your knowledge, and to surround yourself with experts who can advise you well. Be driven by values and not confidence in your own knowledge. Gather intellectual giants around you, and stand on their shoulders.

Modi did not do this in the case of demonetisation, which he carried out against the advice of every expert he consulted. We all know the damage it caused to the economy.

The other learning from this is for all of us. How do we make sense of the world? By connecting dots. An ankhon-dekhi approach will get us very few dots, and our view of the world will be blurred and incomplete. The best way to gather more dots is reading. The more we read, the better we understand the world, and the better the decisions we take. When we can experience a thousand lives through books, why restrict ourselves to one?

A good man with noble intentions can make bad decisions with horrible consequences. The only way to hedge against this is by staying humble and reading more. So when you finish reading this piece, think of an unread book that you’d like to read today – and read it!

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

This is the 24th installment of The Rationalist, my column for the Times of India.

Back in the last decade, I was a cricket journalist for a few years. Then, around 12 years ago, I quit. I was jaded as hell. Every game seemed like déjà vu, nothing new, just another round on the treadmill. Although I would remember her fondly, I thought me and cricket were done.

And then I fell in love again. Cricket has changed in the last few years in glorious ways. There have been new ways of thinking about the game. There have been new ways of playing the game. Every season, new kinds of drama form, new nuances spring up into sight. This is true even of what had once seemed the dullest form of the game, one-day cricket. We are entering into a brave new world, and the team leading us there is England. No matter what happens in the World Cup final today – a single game involves a huge amount of luck – this England side are extraordinary. They are the bridge between eras, leading us into a Golden Age of Cricket.

I know that sounds hyperbolic, so let me stun you further by saying that I give the IPL credit for this. And now, having woken up you up with such a jolt on this lovely Sunday morning, let me explain.

Twenty20 cricket changed the game in two fundamental ways. Both ended up changing one-day cricket. The first was strategy.

When the first T20 games took place, teams applied an ODI template to innings-building: pinch-hit, build, slog. But this was not an optimal approach. In ODIs, teams have 11 players over 50 overs. In T20s, they have 11 players over 20 overs. The equation between resources and constraints is different. This means that the cost of a wicket goes down, and the cost of a dot ball goes up. Critically, it means that the value of aggression rises. A team need not follow the ODI template. In some instances, attacking for all 20 overs – or as I call it, ‘frontloading’ – may be optimal.

West Indies won the T20 World Cup in 2016 by doing just this, and England played similarly. And some sides began to realise was that they had been underestimating the value of aggression in one-day cricket as well.

The second fundamental way in which T20 cricket changed cricket was in terms of skills. The IPL and other leagues brought big money into the game. This changed incentives for budding cricketers. Relatively few people break into Test or ODI cricket, and play for their countries. A much wider pool can aspire to play T20 cricket – which also provides much more money. So it makes sense to spend the hundreds of hours you are in the nets honing T20 skills rather than Test match skills. Go to any nets practice, and you will find many more kids practising innovative aggressive strokes than playing the forward defensive.

As a result, batsmen today have a wider array of attacking strokes than earlier generations. Because every run counts more in T20 cricket, the standard of fielding has also shot up. And bowlers have also reacted to this by expanding their arsenal of tricks. Everyone has had to lift their game.

In one-day cricket, thus, two things have happened. One, there is better strategic understanding about the value of aggression. Two, batsmen are better equipped to act on the aggressive imperative. The game has continued to evolve.

Bowlers have reacted to this with greater aggression on their part, and this ongoing dialogue has been fascinating. The cricket writer Gideon Haigh once told me on my podcast that the 2015 World Cup featured a battle between T20 batting and Test match bowling.

This England team is the high watermark so far. Their aggression does not come from slogging. They bat with a combination of intent and skills that allows them to coast at 6-an-over, without needing to take too many risks. In normal conditions, thus, they can coast to 300 – any hitting they do beyond that is the bonus that takes them to 350 or 400. It’s a whole new level, illustrated by the fact that at one point a few days ago, they had seven consecutive scores of 300 to their name. Look at their scores over the last few years, in fact, and it is clear that this is the greatest batting side in the history of one-day cricket – by a margin.

There have been stumbles in this World Cup, but in the bigger picture, those are outliers. If England have a bad day in the final and New Zealand play their A-game, England might even lose today. But if Captain Morgan’s men play their A-game, they will coast to victory. New Zealand does not have those gears. No other team in the world does – for now.

But one day, they will all have to learn to play like this.

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

Hello!

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

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

Can i collect coverage for this signal?

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I’m not talking about carnival funhouse mirrors, but rather the different options for mirroring symbols, vias, and bond fingers in your IC Package layout. The Allegro Package Designer Plus and SiP Layout tools have two distinct styles of m...(read more)

  A few weeks ago, we talked about template text labels for design-specific information. There, we were focused on labels that are specific to the design as a whole: revision information, dates, authors, etc. Today, we’re looking at a diff...(read more)

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

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In the Allegro back-end layout products like Allegro Package Designer Plus, it would be reasonable to assume that the most often used command is none other than “show element” (shortcut key F4). This command, runnable at nearly any t...(read more)

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I've redesigned a custom TO220FLAT Package

First I created a TO220shape.ssm  with PCB Editor. Then I created a surface mount T220build.pad in Padstack Editor using TO220shape.ssm. Then I created a TO220FLAT.psm in PCB Editor. I placed 3 Connect pins and 9 Mechanical pins for the TO220 TAB, using standard through-hole pads for better current handling.

Adding those Mechanical pins created many DRC errors caused by the proximity of those pads attached to the TO220shape.

Thru Pin to SMD Pin Spacing (-200.0 0.0) 5 MIL OVERLAP DEFAULT NET SPACING CONSTRAINTS Mechanical Pin "Pad50sq30d" Pin "T220build, 2"

I corrected the situation (so I though) by Waiving those DRC errors, thinking that they could not cause any problem and because that’s what I want, i.e.: 9 through-holes under the TO220 device. The idea being that when this device is mounted flat on the PCB it could carry lots of current via 9 pads that could make a good high current conductor to inner layers.

I then saved the Package and updated all related footprint schematic parts  in Capture. Created a new Netlist. Then I imported the new logic into PCB Editor to reflect that change. When the File > Import > Logic is finished I get no feedback error! (which, for me is a substantial achievement in itself)

Now, in the Design Window I see all those DRC errors popping up again, despite the fact that I waived those DRCs back in the Padstack edition. If I run a Design Rule Check (DRC) Report I will see all those DRC listed again. Now, I understand that I can go ahead and waive all those DRCs (100 in total) but I’m thinking there is got to be a better way of doing this.

Please, any advise is welcome. Thanks

Hi All,

I've just about to finish my first PCB layout, and I want to understand some 2 issues better:

1. Soldermask layer: when exactly do we want to define for some SMT pad (say at Pad Designer tool), to have soldermask top and when we want to define solermask bottom? 

if it's a TH pad, I guess we always want to define both layers soldermask (top, bottom), because the pads are crossing all the layers. However, if it's a SMT pad, which SM we want?

2. Pastemask layer: is this layer necessary for the gerber files generation, when we have SMT components in our circuit?

And again, when we define for a TH/SMT pads pastemask top, and when Pastemask bottom?

Thanks!

Hi,

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

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

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

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

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

I've heard lots of people asking for a way to generate Makefiles for Specman code, and it seems there are some who don't use "irun" which takes care of this automatically. So I wrote this little utility to build a basic Makefile based on the compiled and loaded e code.

It's really easy to use: at any time load the snmakedeps.e into Specman, and use "write makefile <name> [-ignore_test]".
This will dump a Makefile with a set of variables corresponding to the loaded packages, and targets to build any compiled modules.
Using -ignore_test will avoid having the test file in the Makefile, in case you switch tests often (who doesn't?).

It also writes a stub target so you can do "make stub_ncvlog" or "make stub vhdl" etc.

The targets are pretty basic, I thought it was more useful to #include this into the main Makefile and define your own more complex targets / dependencies as required.

The package uses the "reflection" facility of the e language, which is now documented since Specman 8.1, so you can extend this utility if you want (please share any enhancements you make).

 Enjoy! :-)

Steve.

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

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

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

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

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

* Comparing data of previously retrieved Matlab arrays

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

* Convert Matlab arrays into e-lists

Happy coding!

Team Specman

Just in time for the holidays, inside the posted tar ball is some code to solve 9x9 Sudoku puzzles with the Assertion-Driven Simulation (ADS) capability of Incisive Enterprise Verifier (IEV). Enjoy! Joerg Mueller Solutions Engineer for Team Verify

Try looking at www.solidwoodkitchen.co.uk. They have some amazing designs and prices.

Kitchen Design Manchester

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

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.

Hello,

I am using ultrasim Version 18.1.0.314.isr5  64bit 03/26/2019 06:33 (csvcm20c-2).

When I run my netlist, ultrasim is blocked in the first DC stage and takes forever. Then it will fail or never progress. I am using a 22nm BSIMBULK model. I tried to tune different accuracy and convergence aids options but noting works.

 When I run the same netlist with spectre it works fine with no problem.

Also, If I use another model (not BULKSIM), ultrasim will work and converge with no problem.

My first feeling is that ultrasim has a problem with using BSIMBULK model.

Could you please advice,

Thank you,

Kotb

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)

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)

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. 

Key Findings:  There are a host of issues that arise in mixed-signal verification.  As discussed in earlier blogs, the industry trends indicate that teams need to prepare themselves for a more mixed world.  The good news is that these top five pitfalls are all avoidable.

It’s always interesting to study the human condition.  Watching the world through the lens of mixed-signal verification brings an interesting microcosm into focus.  The top 5 items that I regularly see vexing teams are:

1. When there’s a bug, whose problem is it?
2. Verification team is the lightning rod
3. Three (conflicting) points of view
4. Wait, there’s more… software
5. There’s a whole new language

Reason 1: When there’s a bug, whose problem is it?

It actually turns out to be a good thing when a bug is found during the design process.  Much, much better than when the silicon arrives back from the foundry of course. Whether by sheer luck, or a structured approach to verification, sometimes a bug gets discovered. The trouble in mixed-signal design occurs when that bug is near the boundary of an analog and a digital domain.

Figure 1.   Whose bug is it?

Typically designers are a diligent sort and make sure that their block works as desired. However, when things go wrong during integration, it is usually also project crunch time. So, it has to be the other guy’s bug, right?

A step in the right direction is to have a third party, a mixed-signal verification expert, apply rigorous methods to the mixed-signal verification task.  But, that leads to number 2 on my list.

Reason 2: Verification team is the lightning rod

Having a dedicated verification team with mixed-signal expertise is a great start, but what can typically happen is that team is hampered by the lack of availability of a fast executing model of the analog behavior (best practice today being a SystemVerilog real number model – SV_RNM). That model is critical because it enables orders of magnitude more tests to be run against the design in the same timeframe. 

Without that model, there will be a testing deficit. So, when the bugs come in, it is easy for everyone to point their finger at the verification team.

Figure 2.  It’s the verification team’s fault

Yes, the model creates a new validation task – it’s validation – but the speed-up enabled by the model more than compensates in terms of functional coverage and schedule.

The postscript on this finger-pointing is the institutionalization of SV-RNM. And, of course, the verification team gets its turn.

Figure 3.  Verification team’s revenge

Reason 3: Three (conflicting) points of view

The third common issue arises when the finger-pointing settles down. There is still a delineation of responsibility that is often not easy to achieve when designs of a truly mixed-signal nature are being undertaken.  

Figure 4.  Points of view and roles

Figure 4 outlines some of the delegated responsibility, but notice that everyone is still potentially on the hook to create a model. It is questions of purpose, expertise, bandwidth, and convention that go into the decision about who will “own” each model. It is not uncommon for the modeling task to be a collaborative effort where the expertise on analog behavior comes from the analog team, while the verification team ensures that the model is constructed in such a manner that it will fit seamlessly into the overall chip verification. Less commonly, the digital design team does the modeling simply to enable the verification of their own work.

Reason 4: Wait, there’s more… software

As if verifying the function of a chip was not hard enough, there is a clear trend towards product offerings that include software along with the chip. In the mixed-signal design realm, many times this software has among its functions things like calibration and compensation that provide a flexible way of delivering guards against parameter drift. When the combination of the chip and the software are the product, they need to be verified together. This puts an enormous premium on fast executing SV-RNM.

Figure 5.   There’s software analog and digital

While the added dimension of software to the verification task creates new heights of complexity, it also serves as a very strong driver to get everyone aligned and motivated to adopt best known practices for mixed-signal verification.  This is an opportunity to show superior ability!

Figure 6.  Change in perspective, with the right methodology

Reason 5: There’s a whole new language

Communication is of vital importance in a multi-faceted, multi-team program.  Time zones, cultures, and personalities aside, mixed-signal verification needs to be a collaborative effort.  Terminology can be a big stumbling block in getting to a common understanding. If we take a look at the key areas where significant improvement can usually be made, we can start to see the breadth of knowledge that is required to “get” the entirety of the picture:

• Structure – Verification planning and management
• Methodology – UVM (Unified Verification Methodology – Accellera Standard)
• Measure – MDV (Metrics-driven verification)
• Multi-engine – Software, emulation, FPGA proto, formal, static, VIP
• Modeling – SystemVerilog (discrete time) down to SPICE (continuous time)
• Languages – SystemVerilog, Verilog, Verilog-AMS, VHDL, SPICE, PSL, CPF, UPF

Each of these areas has its own jumble of terminology and acronyms. It never hurts to create a team glossary to start with. Heck, I often get my LDO, IFV, and UDT all mixed up myself.

Summary

Yes, there are a lot of things that make it hard for the humans involved in the process of mixed-signal design and verification, but there is a lot that can be improved once the pain is felt (no pain, no gain is akin to no bugs, no verification methodology change). If we take a look at the key areas from the previous section, we can put a different lens on them and describe the value that they bring:

• Structure – Uniformly organized, auditable, predictable, transparency
• Methodology – Reusable, productive, portable, industry standard
• Measure – Quantified progress, risk/quality management, precise goals
• Multi-engine – Faster execution, improved schedule, enables new quality level
• Modeling – Enabler, flexible, adaptable for diverse applications/design styles
• Languages – Flexible, complete, robust, standard, scalability to best practices

With all of this value firmly in hand, we can turn our thoughts to happier words:

…  stay tuned for more!

 Steve Carlson

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.

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

Cadence_SPB_17.4-2019 + Matlab R2019a

请参考本文档中的步骤进行操作

1，打开BJT_AMP.opj

2，设置Matlab路径

3，打开BJT_AMP_SLPS.slx

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

5，添加模块

6，相同

7，打开pspsim.slx

8，相同

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

orCEFSimpleUI.exe和orCEFSimple.exe

10，相同

我想问一下如何解决，非常感谢！