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Breaking The Three Laws
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Archive for the 'FPMM Methods' Category
Posted by Michael Posner on 25th January 2015
Last week I spent a week in Japan visiting users to discuss their FPGA-based prototyping challenges and explain how Synopsys can help. My overall take-away of the visits was that many companies want to expand their current single FPGA-based prototyping to multi-FPGA but fear the challenges associated with this. The summary of what I explained was pretty simple but to the point. #1 Having a defined methodology, flow and tool set is key. #2 Yes Multi-FPGA is more complex but it’s not as steep of a learning curve as you may think. And that’s it…..
#1 Having a defined methodology, flow and tool set is key
In respect to methodology you of course can refer to the FPGA-based Prototyping Methodology Manual, FPMM. (English and Japanese versions, 英語版と日本語版) I used Google translate so I hope I didn’t just offend the whole of Japan. Read the FPMM and you will become an expert prototyper but we all know that in this age of technology a summary is always nice. This is why I blogged about 3 Phase Approach to Successful Prototyping a while back. Yes, this is the blog with the upside down pyramid which at the time I thought was a great way to show the progression down through a funnel. The three phases are “Make Design FPGA Ready”, this is all about making the ASIC RTL FPGA friendly. “Bring Up Functional Prototype”, this is where you want to get onto the hardware as quickly as possible so you can functionally validate the design. Finally “Optimize Prototyping Performance”, pretty self-explanatory really.
Along with a defined methodology you need to utilize a tool flow which is designed for prototyping. I was amazed in Japan that many companies still tried to use the FPGA vendor tools for prototyping. I have nothing against FPGA vendor tools, they are great for their job which is FPGA synthesis. When I asked about the challenges these customer faced it was the same story I have heard before, ASIC clock conversion, gated clocks, memories and for the few that did multi-FPGA the key challenge was clock/reset synchronization and pin multiplexing. If you want to go fast on the freeway you don’t buy a bicycle you buy a car, it’s the same with prototyping. If you want to prototype buy a tool set which is designed for the purpose. I blogged about ASIC Gated clock conversion a while back, Unlocking the Secrets of ASIC Clock Conversion, which is just one example of a tool set designed for prototyping. Search my blog and you will find a stack more examples of what is possible by the tools these days. You need a tool set which is more than just a FPGA synthesis tool, you need a tool set that understands your challenges and can help with automation and dedicated capabilities.
#2 Yes Multi-FPGA is more complex but it’s not as steep of a learning curve as you may think.
If you have never prototyped before I’m not going to tell you to start doing multi-FPGA prototyping straight away, too many variables to take on at once. Start small, create a single FPGA-based prototype of a subsystem of your design. Don’t fall into the trap of thinking you can get away with using the FPGA vendor tools (see above) use a dedicated FPGA-based prototyping tool. This is exactly why we provide ProtoCompiler DX as part of the HAPS-DX system. ProtoCompiler DX is everything you need to implement the prototype and more as it includes high visibility debug capabilities. Once you have a prototype up and running on a single FPGA, then it’s time to expand, but don’t bite off more than you can chew, again start small. My suggestion is that you do not add anything new to the design you already have operational. Simply select a block or two from the existing design and move them into a 2nd FPGA. Using your multi-FPGA prototype tool, such as ProtoCompiler, get familiar with partitioning and pin multiplex IP insertion. Get familiar with customizing the hardware to match the needs of your design. Abstract Partition Flow Advantage, this is an important step to ensure that you create the highest performance multi-FPGA prototype. Once you have the same design up and running on two FPGA’s and a design flow and expertise in place you are ready for greater things. Go off and be successful in multi-FPGA prototyping.
The weather was pretty nice in Japan, here is the view from the hotel I was staying at:
We had lots of nice meals out, can you guess what was served at this restaurant?
We did a day trip to Shin-Osaka via the bullet train, Shinkansen, what a mean looking train
Nice view of Mount Fuji on the way up
While the Japanese can build a train that goes 200 MPH they have the same problem as the rest of the world, horrible coffee. Luckily when we arrived the local team treated me to vending machine coffee
Of course many may question my judgment for even trying train coffee and vending machine coffee. You have to remember I was jet lagged and this was better than no coffee….. but only marginally.
I met the star of the film, Big Hero6, Bay Max, well at least his inflatable body double
The funny thing is that Bay Max the real character is also inflatable so what this really a body double or his clone?
Posted in FPGA-Based Prototyping, FPMM Methods, Getting Started, Technical, Tips and Traps, Use Modes | No Comments »
Posted by Michael Posner on 14th November 2014
Recently Synopsys promoted that “Synopsys Virtual Prototyping Book Achieves Milestone of More Than 3000 Copies in Distribution to Over 1000 Companies” – http://news.synopsys.com/2014-11-05-Synopsys-Virtual-Prototyping-Book-Achieves-Milestone-of-More-Than-3000-Copies-in-Distribution-to-Over-1000-Companies Virtual Prototyping continues to gain momentum including Hybrid Prototyping, which combines Virtual Prototyping with FPGA-based prototyping. The VP book statistics prompted me to have a look at the FPGA-based Prototyping Methodology Manual, FPMM statistics.
To date there have been over 6000 FPMM downloads across 2800 different companies and over 2500 free books handed out. WOW. I expect a bit of overlap between the two but still that’s got to be over 8000 copies distributed. I’m happy that the FPMM has been able to help so many engineers around the world.
Looking at the challenges facing these prototypers, below image, you can see that conversion of ASIC to FPGA is still rated as #1.
Actually the #2 challenge, clocking issues, really falls into the this same category. As previously blogged, these challenges are not solved with just software or just hardware changes, they are solved by integration. When the software has built in understanding of the hardware and when the hardware can be customized to the needs of the SoC many of the challenges disintegrate.
A great example of the value of integration is the DesignWare IP Prototyping Kits which are part of the Synopsys IP Accelerated Initiative. DesignWare IP prototyping kits deliver a comprehensive IP subsystem which enables immediate productivity for both Hardware and Software engineers. Individually IP & FPGA-based prototyping deliver value but when combined the value is increased. It’s like the 1+1 = 3.
Talking of IP, DesignWare USB 3.1 IP is now available. http://www.synopsys.com/Company/PressRoom/Pages/usb-3-1-news-release.aspx . I have been talking about USB 3.1 for a while now and blogged about it here. You can also find a video of the DesignWare IP for USB 3.1 running on the HAPS-70 systems here https://www.youtube.com/watch?v=isQ7cvuyoTw
Do you have a topic you would like me to blog about? If so, drop me a comment and I’ll pop it in the queue.
Posted in FPGA-Based Prototyping, FPMM Methods, Getting Started, IP Validation, Technical, Tips and Traps | 1 Comment »
Posted by Michael Posner on 30th October 2014
In previous blogs I have spoken a lot about automation, features and capabilities which accelerate time to operational prototype and deliver higher performance enabling you to run more software against your design representation. These capabilities are designed to reduce the need for prototyping expertise and effort…….. but not to zero. Anyone who tells you that no expertise or effort is needed is not telling you the whole truth. This was the basis of this blog, “Breaking the three laws” of which the first law is ASIC are FPGA Hostile! Who can tell me what the other two laws are? I know but this is like a quiz for my readers.
Pictures in the blog are posted large so they are easier to read, click on the picture to see the full view version.
Synopsys has created a simple three phase definition for FPGA-based prototyping, including methodology guidelines and I am happy to share them with you. The three phases split into 1. Make Design FPGA Ready. 2. Bring Up Functional Prototype. 3. Optimize Prototype Performance. Follow these three phases and you will be on a path for FPGA-based prototyping success.
Make Design FPGA Ready
This is probably the most important step as the rule of thumb is garbage in, garbage out. There is only so much automation a tool can deliver so understanding the basic needs and best practices for FPGA-based prototyping is essential. Synopsys ProtoCompiler can help here with automated ASIC to FPGA translation, clock conversion and replication as needed. However you should always follow the best practices defined here to yield better results in the final implementation. Don’t forget, full best practices can be found in the FPMM, FPGA-based Prototyping Methodology Manual.
Bring Up Functional Prototype
Once code is prepared the bring up functional prototype phase is entered. This is the phase with the goal of getting the prototype up and running as quickly as possible, TTFP, enabling the team to hand off a platform to the software developers. The faster they get a platform the most productive they can be. Even if you have traded off a little performance to get the fastest time to prototype your software team will thank you for the fast enablement. ProtoCompiler and HAPS helps here, especially in the partition phase, I recently blogged about this: Abstract Partition Flow Advantage. Another important best practice is to plan your debug needs upfront in this phase, don’t treat it as an afterthought. This is exactly why in the ProtoCompiler flow debug is highlighted ensuring you at least give it some thought.
Optimize Prototype Performance
As you have already delivered an operational prototype to your software team you have a little breathing space now to focus on performance optimizations. In the fast turn-around abstract partition flow ProtoCompiler might have identified some bottlenecks that you skipped past in order to achieve fastest time to prototype. Now you have time to focus on these and other areas of the FPGA-based prototype to squeeze the most out of the solution. An example of this was shared with me recently where the prototype was fully operational at 9 MHz but with a little more effort, new partition and careful analysis of critical paths, the prototype performance was increased to 13 MHz. What a great improvement.
So there it is, three simple phased approach ensuring successful prototyping, enjoy!
Happy Halloween, here is the costume that I built, I call it Atomic Dinosaur. I am a construction spray foam master and it has LED lights down it’s back too!
That’s some crazy eyes I’ve got going on…………….
Posted in FPGA-Based Prototyping, FPMM Methods, Getting Started, Technical, Tips and Traps | Comments Off
Posted by Michael Posner on 28th April 2014
Synopsys just announced ProtoCompiler which is automation and debug software for HAPS FPGA-Based Prototyping Systems. ProtoCompiler is the result of years of R&D effort to generate a tool that addresses prototypers challenges today and built on top of an architecture which can support the needs of prototypers long into the future. ProtoCompiler focuses on the needs of prototypers specifically addressing the need for accelerated bring up as well as providing capabilities which result in higher system performance as compared to existing solutions. In this blog I’ll discuss some of the technical details behind the main tool highlights. Below are the detailed highlihts.
Integrated HAPS hardware and ProtoCompiler software accelerate time to prototype bring-up and improves prototype performance
Automated partitioning across multiple FPGAs decreases runtime from hours to minutes for up to 250 million ASIC gate designs
Enables efficient implementation of proprietary pin multiplexing for 2x faster prototype performance
Captures seconds of trace data with gigabytes of storage capacity for superior debug visibility
(Read to the end of the blog if you also want an update on Mick’s Projects)
Highlight: Integrated HAPS hardware and ProtoCompiler software accelerate time to first prototype bring-up and improves prototype performance
As noted above the goal of ProtoCompiler is to accelerate the bring up of a prototype as well as providing a path to the fastest possible operating performance. ProtoCompiler is unique as it combines hardware/software expertise with intimate knowledge to deliver superior results. Think of it as delivering a HAPS hardware expert packaged up into a format that anyone using the tool can access. ProtoCompiler has deep technical knowledge of the HAPS hardware including configuration, clocking structures, interconnect architecture, pin multiplexing expertise and more. ProtoCompiler is not only a hardware expert, it’s also a software expert. ProtoCompiler is built on top of a state of the art Synopsys proprietary prototyping database that means RTL is effectively processed and incremental and multi-processing techniques can be deployed with ease.
All this results in blazingly fast processing speeds. As an example ProtoCompiler’s area estimation, essential for automated partitioning, can processed 36 Million ASIC gates in less than 4 hours as compared to 22 hours in existing solutions. Now that’s fast!. Thanks to the new data model and incremental modes all subsequent compiles are even quicker.
Highlight: Automated partitioning across multiple FPGAs decreases runtime from hours to minutes for up to 250 million ASIC gate designs
So there are actually two announcements packaged up in this highlight. Starting in reverse ProtoCompiler supports 250 Million ASIC gate and larger designs. Humm, this sounds a little suspect as when HAPS-70 was launched it only supported 144 Million ASIC gates, what does ProtoCompiler know that we don’t? Luckily I know, HAPS-70 can now be scaled to support 288 Million ASIC gates, 2x the capacity. HAPS-70 now supports chaining of any six systems so if you chain six HAPS-70 S48’s you get a total of 288 Million ASIC gates supported which is 24 Xilinx Virtex-7 2000T FPGA’s. All working in one synchronous system.
Any 3 HAPS systems can be chained via our standard control and data exchange cabling, when you go above 3 systems you utilize a synchronization module that manages the system synchronization. Managing clock skew, reset distribution and configuration is all handled automatically. ProtoCompiler understands the hardware capabilities thus making deployment of such a system a snap. No longer do your engineers have to worry about how to distribute clocking, we have done the hard work so you don’t have to. Other vendors “claim” scalability and modularity but if all they are delivering is boards then it’s nothing more than a wild claim. To deploy a scalable and modular system you need a complete solution of software and hardware. You can now prototype SoC designs you thought never possible
The first part of the highlight introduces the new partition technology deployed in ProtoCompiler. ASIC’s are bigger than a single FPGA so you need to quickly partition the design across multiple FPGA’s. Historically this has been a challenge but with ProtoCompiler that challenge has been overcome. The partition engine in ProtoCompiler requires minimal setup before you can apply it to your design. There are four simple steps to setup the partition engine #1 Create target system, basically which system(s) you are compiling to. #2 Establish basic constraints which are things like blocks of IO. #3 Define the design clocks. #4 Propose an interconnect structure. Actually #4 can either be defined telling the partition engine to use a set interconnect architecture or leave it open and let the tool do it. There are advantages of both. By letting the tool pick the needed architecture the resulting system should be higher performance as ProtoCompiler will maximize interconnect to reduce pin multiplexing ratio. In a previously deployed system you may have already set the interconnect and then want the tool to use the available resources so you don’t make any changes to the hardware in the field. ProtoCompiler has the flexibility to do both meeting the needs of new prototype creation and image re-spin after a new RTL code drop.
ProtoCompiler partition engine is FAST, using the same example as above, 36 Million ASIC gates, ProtoCompiler was able to come to an automated solution is 4 minutes!!! WOW. ProtoCompiler provides a huge amount of information as to what it automatically did so that the engineer can quickly review the results and maybe provide ProtoCompiler more guidance to optimize the partition. For example after the first run you might want to lock down select parts of the design and then incrementally run the engine to push it to find a better solution for the rest of the design. As it runs so fast you can do multiple of these optimization iterations in a matter of hours. I’ve played with the tool as I was interested in this particular capability and have to say it’s amazing. I’ve tried the open method and let the tool find a solution for itself, in this mode ProtoCompiler pretty much finds a solution every time. I also played with challenging the tool for example locking the tool to use only 100 IO’s (two HT3 connectors) between FPGA’s. ProtoCompiler quickly finishes and told me that I was crazy and that the design could never be partitioned with my selected interconnect architecture.
Highlight: Enables efficient implementation of proprietary pin multiplexing for 2x faster prototype performance
OK, this is simple, this basically says that ProtoCompiler can automatically deploy the HAPS High Speed Time-Domain Multiplexing (HSTDM). HSTDM is developed and optimized on HAPS and ProtoCompiler packages up this expertize and automated the deployment. The partition engine will automatically select HSTDM and instance it into the prototype design. HSTDM delivers high performance pin multiplexing between multiple FPGA’s. The signals are packaged up, sent across a high performance link and unpacked at the other side. This all happens within one system clock and is completely transparent to the user. No manual intervention, no additional latency, and it’s stable and reliable as HSTDM is tested as part f the HAPS production testing and every system has to pass the minimum HSTDM performance tests. This ensures that when you deploy am image with HSTDM that it runs on every system the image is loaded on. No need to tailor the pin multiplexing implementation for each board like you have to do with other vendors.
Highlight: Captures seconds of trace data with gigabytes of storage capacity for superior debug visibility
ProtoCompiler expands the debug capabilities and grows the HAPS Deep Trace Debug capability which utilizes off-FPGA memory to store debug data. ProtoCompiler provides seamless multi-FPGA debug capabilities on top of a set of other debug capabilities tailored to delivering visibility at the right level of the debug cycle.
In debug one size does not fit all, you need to deploy the right level of debug visibility capability dependent on what you are trying to debug and the specific point you are in the project cycle. Sometimes you want very wide debug visibility with fast incremental turn-around. Later in the design cycle you typically want very, very deep debug windows. ProtoCompiler delivers both, fully automated through the flow, seamless and transparent to the users. And when I say deep, I mean deep, the example below is very typical of the debug window where you can easily capture seconds of debug data.
As usual my blogs got really long. I wrote it in the car while driving from Portland to Eugene. Amazing that I could type all of this and drive at the same time (LOL, only joking I was in the passenger seat)
Anyway, ProtoCompiler is the bees knees and I personally think it revolutionizes FPGA-based prototyping using HAPS. What do you think of ProtoCompiler?
If you have managed to get this far into my blog then congratulations. I’ve been taking it easy this week while I recover from the pneumonia that I came down with. In the evenings I finished off the two mini RC tracked vehicles I had been working on. The basis of both are simple kits which I then modified and added RC receivers and motor controllers to. While I am a grown adult I must admit they are fun to play with. The first is a basic platform RC tracked vehicle which I attached a Lego sheet to. Little did I know that this would be so popular with my son. He has been building towers and all types of structures on top of it.
Why drive your car to a car park when the car park can come to you. No joke that’s what my son said.
Mobile tire store
Bulldozer and sweeper
At the same time I also built a kit that has a shovel that moves on the front. Again I modified it to be radio controlled, including the shovel. This vehicle is a HUGE hit with my son and he has been busy building towers, knocking them down, then tidying them up with the shovel.
There are a couple of video’s of these little things in action on my You Tube page: https://www.youtube.com/user/MrMickPosner (and a video of my chicken food winch system)
Posted in Admin and General, ASIC Verification, Bug Hunting, Debug, Early Software Development, FPGA-Based Prototyping, FPMM Methods, Getting Started, HW/SW Integration, In-System Software Validation, Man Hours Savings, Mick's Projects, Milestones, Project management, System Validation, Technical | Comments Off
Posted by Michael Posner on 16th March 2014
Is this the future of wearable technology?
LOL, no…. well maybe…..
There are lots of questions on if wearables will bring the end of the Smartphone, I personally think these two technologies will co-exist. I like the idea of wearing my technology but there are many people that don’t thus there should be a place for both technologies for a while yet. Of course for anyone who travels a lot like me they will know that the airport security creates a new issue not previously encountered. I use a fitbit which is a small step tracker and I wear this on my trouser (pant) pocket. It pretty much lives in this spot and I’ve almost put it through the washing machine when I’ve forgotten to take it off. The problem is that this little device has become a part of my life and when going through airport security I’ve also forgotten to take it off which leads to an extra search pat down. A simple solution to this would be for me to remember to take it off but it would be nice if these devices are security certified of something like that.
When it comes to prototyping these deeply embedded SoC designs you will find out that while the form factor is small and simple the SoC designs are not. These designs are multi-million ASIC gates so when they are prototyped using FPGA’s the challenges of handling non-FPGA code, multi-FPGA partitioning and prototype assembly must be overcome. I visited a load of customers last week while traveling internationally and the common theme at the meetings was discussion around how to enable complex FPGA-based prototyping without the need for in-depth specific expertise. The first place to start is to put a methodology in place to define a flow supporting FPGA-based prototyping making a part of the larger SoC project. The FPGA-based Prototyping Methodology Manual, FPMM, is the perfect place to start in defining what is needed as part of this flow.
I had the pleasure of traveling with Rene Richter, one of the co-authors of the FPMM. In the picture above you can see him explaining the basis of multi-FPGA partitioning and how to utilize pin multiplexing. His expertise helped a lot of customers last week but he was the first to say that everything he explained was already documented in the FPMM.
This week’s call to action, download the FPMM if you have not already done so………… and read it.
I was thinking that it might be time to work on the 2nd revision, updating the FPMM with information on how FPGA-based prototyping has evolved over the last couple of years, what do you think? What do you think has changed in FPGA-based prototyping which should be documented?
Posted in ASIC Verification, FPGA-Based Prototyping, FPMM Methods, Getting Started, Technical, Tips and Traps | Comments Off
Posted by Michael Posner on 10th January 2014
As it’s my first blog of 2014 (Happy New year and all that) I wanted to reflect back on 2013 and what better way to do that than review the best of the best of my blog postings from 2013. So drum roll please… here is my short list of cracking blog posts from 2013 in chronological order. This is not a list of all the blogs (but it did turn out to be a big list) just the ones that I personally think have the most valuable FPGA-based prototyping information.
Also, check out my new Blog Bio Photo –> 007 Style !!
How IO Interconnect Flexibility and Signal Mux Ratios Affect System Performance
One of the “Breaking The Three Laws” is that your SoC partitioned blocks typically have more signals than physical IO’s on the FPGA. Technically this is not one of the three laws but it should have been and as I own this blog I can make one more up. Welcome to the Breaking The Four [...]
Direct Route or Take the Bus?
Last week’s blog was on direct interconnect density and the effect it has on pin mux ratios. The example focused on using HSTDM but one of the readers correctly pointed out that interconnect density effects any pin muxing scheme, not only HSTDM. The rule of thumb is the greater the density of interconnect routes the [...]
UFC: Cables Vs. PCB Traces
UFC: Cables Vs. PCB Traces With the new HAPS-70 all cable based interconnect architecture we often get asked about overall raw performance of the cables vs. PCB traces. Below is the data on the raw cable and new HapsTrak 3 connector performance. This in itself shows that the cable and connector architecture are cable of running [...]
Jim Hogan falls prey to HAPS cloak of invisibility
I used to own a Ford F350 truck and it was huge with the long wheel base, full bed, extended crew cab measuring a length of about 25 feet (8 meters). The problem was that it came installed with a cloak of invisibility. I didn’t know it had a cloak of invisibility when I purchased [...]
EDACafe Video’s and the best dressed presenter
While at DAC, EDACafe video interviewed me discussing the HAPS-70 FPGA-based prototyping solutions. You can find the video here: http://www10.edacafe.com/video/Synopsys-Mick-Posner-Director-Product-Marketing/40055/media.html I liked the interview style and the whole interview was shot in one take, no breaks and was completed in less than 5 minutes. I think you will find the video informative so please watch [...]
Complex SoC Prototyping using Xilinx Virtex-7 based HAPS-70 Systems
At the recent SNUG UK Paul Robertson from Broadcom presented a paper on their use of FPGA-Based Prototyping for their current generation of SoC’s. For those with Synopsys SolvNet access the paper can be found by following this link: http://www.synopsys.com/Community/SNUG/UK/Pages/Abstracts.aspx?loc=UK&locy=2013#C1 Based on participant votes Paul was awarded with the prestigious “Best of SNUG” award. Congratulations [...]
Understanding IP and IP to SoC Prototyping
I’m presenting at the quarterly GSA Intellectual Property (IP) Working Group Meeting this morning and while reviewing my slides I thought I would blog on a couple of aspects of IP (RTL blocks) and IP to SoC Prototyping. I’ve blogged on this topic before but it was ages ago and even I’ve forgotten what I spoke [...]
Do you use a hammer to put in a screw?
This week I was asked to compare the Synopsys HAPS systems to FPGA vendor evaluation boards. I only have good things to say about the FPGA vendor evaluation boards but when comparing these evaluation boards to HAPS for serious FPGA-Based Prototyping I just said, “That’s like using a hammer to put in a screw”. A [...]
Designing an Electrochemical Cell
A couple of folks complained that my last blogs have been a bit long and boring. (Boring! Me?) So I would like to start this week and apologize to all my 5th Grade readers, I’ll try harder in the future to use smaller words and more pictures. The good news is that this week is [...]
Accelerating Prototyping Hardware Assembly
This week I wanted to focus on a discussion around prototyping hardware assembly. Prototype hardware assembly is the process to tailor FPGA-prototyping hardware to meet the needs of the project. The first type of prototype assembly would be to build a custom platform directly matching the projects requirements. The building of prototyping hardware is the [...]
Xilinx FPGA’s for FPGA-Based Prototyping
If we look at the FPMM survey respondent data it’s clear to see that the favored FPGA device for FPGA-based prototyping is Xilinx devices This week Xilinx announced the Virtex® UltraScale™ VU440 3D IC. http://press.xilinx.com/2013-12-10-Xilinx-Doubles-Industrys-Highest-Capacity-Device-to-4-4M-Logic-Cells-Delivering-Density-Advantage-that-is-a-Full-Generation-Ahead This is the device that Xilinx wants the future generation of FPGA-based prototyping hardware to make use of. Rather than [...]
Tear down of the new HAPS-DX FPGA-based prototyping system
I’ve talked about streamlining IP to SoC prototyping and the use modes that prototypers use for IP validation. This week Synopsys announced the new HAPS Developer eXpress (HAPS-DX) prototyping system. This new HAPS-DX system is perfect for complex IP and subsystem prototyping and ties in nicely with the flow that I have been blogging about [...]
Posted in Debug, FPGA-Based Prototyping, FPMM Methods, Getting Started, In-System Software Validation, Technical, Tips and Traps | Comments Off
Posted by Michael Posner on 30th September 2013
I was recently talking to a customer who found that deploying FPGA-based prototyping was a challenge. This was a customer who had only every done simulation for verification purposes. Their last chip incorporated dual embedded processors and unfortunately they had to re-spin the silicon due to a hardware bug that they found only when running the real software. This bug was devastating, the cost was huge as it included the physical costs of the re-spin but worst was the revenue hit from being late to market. This company knew it had to adopt FPGA-Based Prototyping to enable early software development, HW/SW integration and System Validation all PRE-SILICON. The goal was to run the actual software against the hardware and identify HW/SW bugs before code freeze and tape-out.
The process to bring up a prototype was not smooth, they made a couple of key mistakes which I will share with you in an effort to help you avoid these in the future.
#1 – ASIC Code is not FPGA friendly
This is #1 rule from the FPGA-based Prototyping methodology Manual. Their code was full of ASIC specific instances that challenged the initial bring up. One of the problems was that the customer *thought* they could use the FPGA vendor tools for the synthesis. While the FPGA vendors tools seem attractive as they are close to free they do not offer any in-depth prototyping capabilities such as gated clock conversion, DesignWare support and ASIC block conversion. The customer is now looking at utilizing the Synopsys prototyping software tools that provide these capabilities in addition to offering many automated multi-FPGA prototyping capabilities.
#2 Wasted time developing in-house FPGA Boards
The customer thought that as they can design multi-million ASIC gate SoC’s of course they can design a PCB with a couple of FPGA’s on it. Sadly this choice delayed the start of the prototyping project as developing a PCB like this and managing clocking, configuration and debug is not as easy as it seems. The customer spun the PCB twice before getting a platform which provided basic function. After all this the platform stilled lacked specific debug capabilities which limited the customers productivity. The customer will not make this mistake again and is looking to deploy a commercially available FPGA-based prototyping system such as HAPS for their next project.
#3 Tried to bring up the whole SoC prototype at once
Classic mistake. The funny thing is that within simulation the customer brings up individual design blocks and only when each has past it’s hello world and basic functionality tests does it get integrated into a larger SoC verification environment. This is exactly the same as what you should be doing for FPGA-based prototyping. Bring up individual blocks and only when they are operational do you instantiate them into the SoC level. This way you are not debugging multiple issues at once that everybody knows is a very time consuming process.
The customer made other mistakes but the above ones were the worst offenders. In general the customer lacked FPGA expertise and could have really benefited from expert assistance. This is exactly where Synopsys can help, we offer expert services, expert support and expert local application experts.
The one thing that this customer stated that I 100% agree with was that it will be easier the 2nd time around. Exactly, they have built up internal expertise and plan on utilizing available products to improve the flow and the designers productivity. What the customer wishes they had done was to involve Synopsys from the start and utilized our services team to provide FPGA-based prototyping assistance at the start of the project. This would have jump started their effort. By using the Synopsys prototyping software and HAPS system the customer would not have wasted valuable time in creating a flow and designing and debugging hardware. The bonus to using the Synopsys tools and hardware is that the customer could have leveraged the extensive support infrastructure of Synopsys FPGA R&D and CAE experts as well as the globally located Application Consultant experts. Synopsys, the home of the Prototyping Super hero’s
Don’t make the same mistake as this customer!
Did your company have a similar experience, let me know about it.
Below is my favorite spam message of the week. Spammers, work out what the blog is talking about before bothering to spam it. Hot tubs, come on, that has nothing to do with FPGA-based prototypes. And nobody wants a “used” hot tub, that’s just gross….
Posted in ASIC Verification, Debug, FPGA-Based Prototyping, FPMM Methods, Getting Started, In-System Software Validation, Project management, Technical, Tips and Traps | Comments Off
Posted by Michael Posner on 7th September 2013
Guest Blog Alert – Doug Amos, author of the FPGA-based Prototyping Methodology.
Thanks, Mick, for allowing me to guest blog on “Breaking the Three Laws”. I’ve really enjoyed reading blog and hearing where FPGA-based Prototyping has been going recently. Apparently, sometimes at a scary speed around a racing track (I’d love to have a ride in that Subaru, but I don’t think it has a passenger seat).
The reason for this guest slot is to reflect on a milestone, and look back on how far we’ve come. What’s the milestone? Well, it’s around a 1000 days since I froze the content of the FPMM (if you are a purist engineer then you can wait until 1024 days to read this, if you prefer). 1000 days sounds like a lot of time, but really is it a lot of progress? How has it worked out for you?
Let’s see how far we’ve come . . .
In November 2011 (for ‘twas then), Xilinx and Synopsys and our more advanced users, were pioneering the use of Virtex 6 FPGAs, prototyping designs of pretty decent speed (21% of prototypes running between 100 and 200 MHz) and targeting in-house developed boards (by a small but significant majority). I know this from talking with users at the time, but also because I can look back at the earliest survey data from those of you who kindly downloaded the FPMM.
The most recent survey data, however, shows some differences . . .
- Prototypes are getting faster (over 33% of designs are now running between 100 and 200MHz).
- More prototypes are being used for System Integration.
- More people now use commercial FPGA Prototype solutions, rather than make their own boards.
Hopefully, dear reader, it is obvious that these three observations are inter-related. There are probably other reasons which will vary from project to project, but the trend away from starting your FPGA-based Prototype by first making a board is pronounced. So post a comment and let Mick and I know about your successes with FPGA-based prototyping
Posted in FPGA-Based Prototyping, FPMM Methods | Comments Off
Posted by Michael Posner on 2nd August 2013
This week we are going to talk about the PCIe connected prototype for RTL block and IP validation and again discuss the benefits of using the loop concept.
The PCIe connected prototyping use case is used to meet the need for an effective and high performance method to validate the RTL design under test against software without the need to model a whole SoC. The design under test is connected to a PCIe core, such as the DesignWare PCIe End Point to create a physical link from the FPGA-based prototype to a host machine. Typically a thin glue logic layer is used to bridge from the PCIe core bus to the DUT bus. The physical link is in the form of a connection from the FPGA-based prototype such as the PCIe MGB kit for HAPS that includes a host plug in card. The PCIe core is visible on the hosts PCIe bus and acts as a transparent interface with mapping to the DUT’s registers and data bus.
With a PCIe connected prototype up and running you can write custom software to exercise the DUT and even run standard software drivers such as you have for USB and SATA which are native to the hosts OS. The huge advantage of the PCIe connected prototype is the PCIe link also has high bandwidth so the DUT can be performance stress tested. Here is an example of the PCIe connected prototype in action utilized in the DesignWare USB 3.0 video: http://www.youtube.com/watch?v=MTGBz–4tVY I like this example as not only does it show software running on the host controlling the DUT and high performance data streaming but it features my friend Eric J
So great you have a standalone validation platform but what about integration into the SoC level prototype????? That’s where the Loop Concept comes in.
The Loop Concept is an elegant and very simple idea that breaks out the DUT from the logic supporting the DUT validation. In our case above we have applied the loop concept to the PCIe connected prototype but it could be just as easily applied to the standalone or in fact any type of RTL block and IP validation prototype. The loop is a set of cables bringing the connection between the DUT and the support logic to the connectors of the prototype and “looping” them back in again. An example could be that you are exposing the DUT’s bus interface to the outside world. Of course to create the loop you may need many IO’s so careful choice of a hardware platform that exposes as many IO’s as possible, such as the HAPS-70 systems, is needed.
When it comes to integrating the DUT into the SoC prototype the loop concept provides two benefits. The loop forces a clean break between the DUT and the support logic infrastructure so it’s easy to identify the RTL needed for the SoC integration. The other use case is that the loop of cables can be unhooked from the support logic and connected directly into the SoC prototyping platform. To be successful with this type of hardware to hardware reuse you need to be using the same hardware series for both the RTL block and SoC level prototypes. Our example illustrates the small HAPS-70 S12 for the RTL block level prototype and the larger HAPS-70 S48 for the SoC level prototype. All HAPS systems support chaining for clock synchronization and configuration. Planning is needed upfront to ensure that the clock and reset schemes are compatible between the DUT and the SoC. The value is in a high level of reuse, accelerated integration of the DUT into the SoC meaning you can become more productive earlier in the design cycle. I love the loop concept, so simple but so powerful.
If you are using the loop concept post me a comment and let me know. If you want more information on how to implement the loop concept post me a comment and I’ll help you setup a reference model.
As you might remember I was at the track a couple of weeks back and for the very first time I actually purchased some pictures from the photographer which attended.
If you look closely in this picture you can see the rear wheel of my car lifted of the ground. I’m not going slow by the way… I’ll be adjusting the rebound setting of my rear suspension so that it can react faster.
I just love this pic, makes my little yellow school bus grocery getter look pretty mean
Next week I’ll discuss the Hybrid Prototyping use mode.
Posted in ASIC Verification, FPGA-Based Prototyping, FPMM Methods, Getting Started, Technical, Tips and Traps | Comments Off
Posted by Michael Posner on 18th July 2013
I’m presenting at the quarterly GSA Intellectual Property (IP) Working Group Meeting this morning and while reviewing my slides I thought I would blog on a couple of aspects of IP (RTL blocks) and IP to SoC Prototyping. I’ve blogged on this topic before but it was ages ago and even I’ve forgotten what I spoke about.
The first is what I like to call the other three laws (not to be confused with the FPMM three laws, who can remember what they are?)
- IP and SoC level prototypes require different capacity solutions
- IP and SoC level prototypes require similar capabilities
- IP prototypes need to be rapidly integrated into SoC level prototypes
Simply put, RTL IP blocks maybe a small fraction of the whole SoC but when you FPGA-based prototype them the only requirement that changes is the capacity (ASIC Gates) of the solution you use.
Thinking about everything I want to write about I think this is going to turn into a blog series as it’s too much for one blog. Yay, that makes the next couple of weeks easy for me.
As mentioned, regardless of the size of the block being prototyped you still need high performance operation, you still need a flexible solution which can be tailored to your designs needs, you still need debug capabilities and an easy to use implemtation tool flow. You can of course get away with less but that just makes your validation and software development task harder and we all have it tough enough already so we strive for an easy life.
Lets start off with looking at the RTL Block/IP prototyping use modes. As usual FPGA-based prototyping of RTL blocks is not done the same way every time but I have been able to create three groupings to help explain how these blocks are typically handled. The three buckets are:- Standalone, PCIe connected and Hybrid.
What I am calling standalone is by far the most popular and easiest use mode to understand. The PCIe connected prototype is the second most popular use mode with the Hybrid prototype being the newest and emerging use mode.
Based on these buckets which use mode do you use for your RTL block/IP prototyping?
In the coming weeks I will explain each use mode in detail and provide tips on structuring the smaller prototyping design so that it can be easily integrated into the larger SoC level prototype.
Posted in ASIC Verification, FPGA-Based Prototyping, FPMM Methods, Getting Started, In-System Software Validation, Technical, Tips and Traps | Comments Off
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