The year 2014 is expected to be a major year for the global semiconductor industry. The industry will and continue to innovate!
Apparently, there are huge expectations from certain segments such as the so-called Internet of Things (IoT) and wearable electronics. There will likely be focus on the connected car. Executives have been stating there could be third parties writing apps that can help cars. Intel expects that technology will be inspiring optimism for healthcare in future. As per a survey, 57 percent of people believe traditional hospitals will be obsolete in the future.
Some other entries from 2013 include Qualcomm, who introduced the Snapdragon 410 chipset with integrated 4G LTE world mode for high-volume smartphones. STMicroelectronics joined ARM mbed project that will enable developers to create smart products with ARM-based industry-leading STM32 microcontrollers and accelerate the Internet of Things.
A look at the industry itself is interesting! The World Semiconductor Trade Statistics Inc. (WSTS) is forecasting the global semiconductor market to be $304 billion in 2013, up 4.4 percent from 2012. The market is expected to recover throughout 2013, driven mainly by double digit growth of Memory product category. By region, all regions except Japan will grow from 2012. Japan market is forecasted to decline from 2012 in US dollar basis due to steep Japanese Yen depreciation compared to 2012.
WSTS estimates that the worldwide semiconductor market is predicted to grow further in 2014 and 2015. According to WSTS, the global semiconductor market is forecasted to be up 4.1 percent to $317 billion in 2014, surpassing historical high of $300 billion registered in 2011. For 2015, it is forecasted to be $328 billion, up 3.4 percent.
All product categories and regions are forecasted to grow positively in each year, with the assumption of macro economy recovery throughout the forecast period. By end market, wireless and automotive are expected to grow faster than total market, while consumer and computer are assumed to remain stagnant.
Now, all of this remains to be seen!
Earlier, while speaking with Dr. Wally Rhines of Mentor, and Jaswinder Ahuja of Cadence, both emphasized the industry’s move to 14/16nm. Xilinx estimates that 28nm will have a very long life. It also shipped the 20nm device in early Nov. 2013.
In a 2013 survey, carried out by KPMG, applications markets identified as most important by at least 55 percent of the respondents were: Mobile technology – 69 percent; Consumer – 66 percent; Computing – 63 percent; Alternative/Renewal Energy – 63 percent; Industrial – 62 percent; Automotive – 60 percent; Medical – 55 percent; Wireline Communications – 55 percent.
Do understand that there is always a line between hope and forecasts, and what the end result actually turns out to be! In the meantime, all of us continue to live with the hope that the global semiconductor will carry on flourishing in the years to come. As Brian Fuller, Cadence, says, ‘the future’s in our hands; let’s not blow it!’
Agnisys Inc. was established in 2007 in Massachusetts, USA, with a mission to deliver innovative automation to the semiconductor industry. The company offers affordable VLSI design and verification tools for SoCs, FPGAs and IPs that makes the design verification process extremely efficient.
Agnisys’ IDesignSpec is an award winning engineering tool that allows an IP, chip or system designer to create the register map specification once and automatically generate all possible views from it. Various outputs are possible, such as UVM, OVM, RALF, SystemRDL, IP-XACT etc. User defined outputs can be created using Tcl or XSLT scripts. IDesignSpec’s patented technology improves engineer’s productivity and design quality.
The IDesignSpec automates the creation of registers and sequences guaranteeing higher quality and consistent results across hardware and software teams. As your ASIC or FPGA design specification changes, IDesignSpec automatically adjusts your design and verification code, keeping the critical integration milestones of your design engineering projects synchronized.
Register verification and sequences consume up to 40 percent of project time or more when errors are the source of re-spins of SoC silicon or an increase in the number of FPGA builds. IDesignSpec family of products is available in various flavors such as IDSWord, IDSExcel, IDSOO and IDSBatch.
IDesignSpec more than a tool for creating register models!
Anupam Bakshi, founder, CEO and chairman, Agnisys, said: “IDesignSpec is more than a tool for creating register models. It is now a complete Executable Design Specification tool. The underlying theme is always to capture the specification in an executable form and generate as much code in the output as possible.”
The latest additions in the IDesignSpec are Constraints, Coverage, Interrupts, Sequences, Assertions, Multiple Bus Domains, Special Registers and Parameterization of outputs.
“IDesignSpec offers a simple and intuitive way to specify constraints. These constraints, specified by the user, are used to capture the design intent. This design intent is transformed into code for design, verification and software. Functional Coverage models can be automatically generated from the spec so that once again the intent is captured and converted into appropriate coverage models,” added Bakshi.
Using an add-on function of capturing Sequences, the user is now able to capture various programming sequences in the spec, which are translated into C++ and UVM sequences, respectively. Further, the interrupt registers can now be identified by the user and appropriate RTL can be generated from the spec. Both edge sensitive and level interrupts can be handled and interrupts from various blocks can be stacked.
Assertions can be automatically generated from the high level constraint specification. These assertions can be created with the RTL or in the external files such that they can be optionally bound to the RTL. Unit level assertions are good for SoC level verification and debug, and help the user in identifying issues deep down in the simulation hierarchy.
The user can now identify one or more bus domains associated with Registers and Blocks, and generate appropriate code from it. Special Registers such as shadow registers and register aliasing is also automatically generated.
Finally all of the outputs such as RTL, UVM, etc., can be parameterized now, so that a single master specification can be used to create outputs that can be parameterized at the elaboration time.
How is IDesignSpec working as chip-level assertion-based verification?
Bakshi said: “It really isn’t an assertion tool! The only assertion that we automatically generate is from the constraints that the user specifies. The user does not need to specify the assertions. We transform the constraints into assertions.”
Selection of the right on-chip network is critical to meeting the requirements of today’s advanced SoCs. There is easy IP integration with IP cores from many sources with different protocols, and an UVM verification environment.
John Bainbridge, staff technologist, CTO Office, Sonics Inc., said that it optimizes the system performance. Virtual channels offer efficient resource usage – saves gates and wires. The non-blocking network leads to an improved system performance. There are flexible topology choices with optimal network to match requirements.
Power management is key with advanced system partitioning, and an improved design flow and timing closure. Finally, the development environment allows easy design capture and has performance analysis tools.
For the record, there are several SoC integration challenges that need to be addressed, such as IP integration, frequency, throughput, physical design, power management, security, time-to-market and development costs.
SGN exceeds requirements
SGN met the tablet performance requirement with fabric frequency of 1066MHz. It has an efficient gate count of 508K gates. There are features such as an advanced system partitioning, security and I/O coherency. There is support for system concurrency as well as advanced power management.
Sonics offers system IP solutions such as SGN, a router based NoC solution, with flexible partitioning and VC (Virtual Channel) support. The frequency is optimized with credit based flow control.
SSX/SLX is message based crossbar/ShareLink solutions based on interleaved multi-channel technology. It has target based QoS with three arbitration levels. The SonicsExpress is for power centric clock domain crossing. There is sub-system re-use and decoupling. The MemMax manages and optimizes the DRAM efficiency while maintaining system QoS. There is run-time programmability for all traffic types. The SonicsConnect is a non-blocking peripheral interconnect.
About 318 engineers and managers completed a blind, anonymous survey on ‘On-Chip Communications Networks (OCCN), also referred to as an “on-chip networks”, defined as the entire interconnect fabric for an SoC. The on-chip communications network report was done by Sonics Inc. A summary of some of the highlights is as follows.
The average estimated time spent on designing, modifying and/or verifying on-chip communications networks was 28 percent (for the respondents that knew their estimate time).
The two biggest challenges for implementing OCCNs were meeting product specifications and balancing frequency, latency and throughput. Second tier challenges were integrating IP elements/sub-systems and getting timing closure.
As for 2013 SoC design expectations, a majority of respondents are targeting a core speed of at least 1 GHz for SoCs design starts within the next 12 months, based on those respondents that knew their target core speeds. Forty percent of respondents expect to have 2-5 power domain partitions for their next SoC design.
A variety of topologies are being considered for respondents’ next on-chip communications networks, including NoCs (half), followed by crossbars, multi-layer bus matrices and peripheral interconnects; respondents that knew their plans here, were seriously considering an average of 1.7 different topologies.
Twenty percent of respondents stated they already had a commercial Network-on-Chip (NoC) implemented or plan to implement one in the next 12 months, while over a quarter plan to evaluate a NoC over the next 12 months. A NoC was defined as a configurable network interconnect that packetizes address/data for multicore SoCs.
For respondents who had an opinion when commercial Networks-on-Chip became an important consideration versus internal development when implementing an SoC, 43 percent said they would consider commercial NoCs at 10 or fewer cores; approximately two-thirds said they would consider commercial NoCs at 20 or fewer cores.
The survey participants’ top three criteria for selecting a Network on Chip were: scalability-adaptability, quality of service and system verification, followed by layout friendly, support for power domain partitioning. Half of respondents saw reduced wiring congestion as the primary reason to use virtual channels, followed by increased throughput and meeting system concurrency with limited bandwidth.
Functional verification is critical in advanced SoC designs. Abey Thomas, verification competency manager, Embitel Technologies, said that over 70 percent effort in the SoC lifecycle is verification. Only one in three SoCs achieves first silicon success.
Thirty percent designs needed three or more re-spins. Three out of four designs are SoCs with one or more processors. Three out of four designs re-use existing IPs. Almost all of the embedded processor IPs have power controllability. Almost all of the SoCs have multiple asynchronous clock domains.
An average of 75 percent designs are less than 20 million gates. Significant increase in formal checking is approaching. Average number of tests performed has increased exponentially. Regression runs now span several days and weeks. Hardware emulation and FPGA prototyping is rising exponentially. There has been a significant increase in verification engineers involved. A lot of HVLs and methodologies are now available.
Verification challenges include unexpected conflicts in accessing the shared resource. Complexities can arise due to an interaction between standalone systems. Next, there are arbitration priority related issues and access deadlocks, as well as exception handling priority conflicts. There are issues related to the hardware/software sequencing, and long loops and unoptimized code segments. The leakage power management and thermal management also pose problems.
There needs to be verification of performance and system power management. Multiple power regions are turned ON and OFF. Multiple clocks are also gated ON and OFF. Next, asynchronous clock domain crossing, and issues related to protocol compliance for standard interfaces. There are issues related to system stability and component reliability. Some other challenges include voltage level translators and isolation cells.
Where are we now? It is at clock gating, power gating with or without retention, multi-switching (multi-Vt) threshold transistors, multi-supply multi-voltage (MSMV), DVFS, logic optimization, thermal compensation, 2D-3D stacking, and fab process and substrate level bias control.
So, what’s needed? There must be be low power methods without impacting on performance. Careful design partitions are needed. The clock trees must be optimized. Crucial software operations need to be identified at early stages. Also, functional verification needs to be thorough.
Power hungry processes must be shortlisted. There needs to be compiler level optimization as well as hardware acceleration based optimization. There should be duplicate registers and branch prediction optimization. Finally, there should be big-little processor approach.
Present verification trends and methodologies include clock partitions, power partitions, isolation cells, level shifters and translators, serializers-deserializers, power controller, clock domain manager, and power information format – CPF or UPF. In low-power related verification, there is on power-down and on power-up. In the latter, the behavioral processes are re-enabled for evaluation.
Open source verification challenges
First, the EDA vendor decides what to support! Too many versions are released in short time frame. Object oriented concepts are used that are sometimes unfit for hardware. Modelling is sometimes done by an engineer who does not know the difference between a clock cycle and motor cycle! Next, there is too much of open source implementations without much documentation. There can be multiple, confusing implementation options as well. In some cases, no open source tools are available. There is limited tech support due to open source.
Power aware simulation steps perform register/latch recognition from RTL design. They perform identification of power elements and power control signals.They support UPF or CPF based simulation. Power reports are generated, which can be exported to a unique coverage database.
Common pitfalls include wrapper on wrapper bugs, eg. Verilog + e wrapper + SV. There is also a dependency on machine generated functional coverage goals. There may be a disconnect between the designer and verification language. There are meaningless coverage reports and defective reference models, as well as unclear and ambiguous specification definition. The proven IP can become buggy due to wrapper condition.
Tips and tricks
There needs to be some early planning tips. Certain steps need to be completed. There should be completion of code coverage targets, completion of functional coverage targets, completion of targeted checker coverage, completion of correlation between functional coverage and checker coverage list, and a complete review of all known bugs, etc.
Tips and tricks include bridging the gap between design language and verification language. There must be use of minimal wrappers to avoid wrapper level bugs. There should be a thorough review of the coverage goals. There should be better interaction between designer and verification engineers. Run using basic EDA tool versions and lower costs.