Products are moving away from being based on printed circuit boards as more complex multi-function chips become available

Automated design tools: a helping box of tricks

Automated design tools let engineers spend more time on innovation and less on repetitive routine tasks.

Design tools have had to keep pace with advances in silicon. As silicon geometries decrease and capabilities increase, development tools have had to match. This has led to some disciplines emerging in the pursuit of faster time-to-market designs.

As products move away from being based on printed circuit boards (PCBs) in favour of complex, multi-function chips, design tools are required to support embedded system design, and validation at system level. They also have to investigate system performance parameters, such as power consumption, before the design is committed to silicon, in order to save development costs and reduce time to market.

Design automation

Wally Rhines, chairman and CEO of Mentor Graphics, remembers that in the early 1970s, engineers “relied on a natural feel for what will and won’t work”. His college syllabus included modelling and algorithms, physical prototyping, characterising and modifying. When he began his career as > < an engineer at Texas Instruments, he used software developed in-house to design integrated circuits. It was not until the 1980s that companies specialising in the development of design tools emerged. Soon it became uneconomic to spend hours on tool development when EDA (electronic design automation) companies could provide them.

Before RTL (register transfer language) was adopted in the late 1980s, developers wrote code for processors using assembler, a low-level programming language, which was translated into machine code. C language programming replaced assembly programming, allowing for an abstracted design for multiple targets instead of a single target, as had been the case with assembler code.

Simon George, a processor specialist at Xilinx, explains that the company has taken the next step and brought RTL to programmable logic. In July, the company released the SDSoC development environment based on C/C++ applications, moving algorithms to the RTL and implementing them in the fabric of the logic. This brings a higher level of abstraction to its Vivado development tool suite.

“RTL descriptions of a design are much more compact and readable by humans than circuit schematics,” explains Paul Cunningham, vice president of R&D at EDA company Cadence. He credits these descriptions with “dramatically improving” logic design productivity, which in turn, leads to up to 100x faster simulations and faster debug. Automation via logic synthesis from RTL for digital design means that some tools have disappeared from an engineer’s toolbox, namely layout and gate tools in the lower layers of the digital design.

Frank Schirrmeister, senior group director of the system and verification group at Cadence, adds: “All the steps at the lower abstraction levels are still in use with the exception of layout and gate tools, which have been automated via logic synthesis from RTL. While the dynamic simulation tools and equivalence checking tools remain unchanged they have been vastly improved in terms of speed, capacity, memory and footprint.”

The move away from low-level circuit design allows designers to focus on the functional features and specification of a design, adding differentiation as well as increasing productivity.

“The ability to describe a design with greater abstraction drives efficiency by virtue of early defect discovery in complex designs,” says Mike Walker, principal engineer at MathWorks. “For example driver assistance systems and the trend towards fully autonomous vehicles means controlling systems ‘fusing’ sensor data from multiple vehicle systems.”

Simulation tools

Today, simulation tools and virtual prototyping speed up validation of design and also allow differentiating functions to be integrated. As devices shrink, the physical means to test for some parameters become unfeasible, prompting the use of simulation tools as probes risk causing damage, and microscopic probes are expensive.

“Automatic testing and validation means an engineer can think of functionality, not lines of code,” says Sudhir Sharma, programme director at physics-based simulator supplier Ansys.
Sharma identifies a convergence of hardware and software, as wireless power charging, Wi-Fi in aircraft, Bluetooth in smartphones and sensors in vehicles are integrated into systems.
This convergence of engineering functions is also seen by Steve Norman, manager of core marketing at Renesas Electronics Europe. “The increased code complexity in smart, connected devices has prompted companies to combine hardware and software development,” he explains.

Norman believes there is a need to “reinvent the development cycle”, so engineers can spend their time on innovating application code rather than integrating core software functions.
In October this year, the company is launching Synergy, a combined hardware and software platform. Engineers can use it to start at the API (application processor interface) level and create differentiated applications, rather than spending time on the low-level tasks, such as setting up peripherals, that can take up to 60 per cent of a developer’s time.

How far this integration of hardware and software development teams will extend is open to debate. Certainly there have been changes, in breaking down the ‘brick wall’ that used to separate hardware and software teams. “The significant change to design tools will be the consolidation and integration of tools,” says Chee Ee Lee, head of product development at semiconductor manufacturer FTDI. Such a move will initiate a process that “takes product specification to implementation and verification, all the way to the back-end flow, integrating with the foundry.”

Open communities

A recent evolution in the market for design tools is their development by distribution companies. RS Components launched the free-of-charge, online PCB design tool DesignSpark PCB in 2010 and followed that with DesignSpark Mechanical, 3D modelling software, in 2013. Both can be used alongside specialist tools, says Mike Brojak, technical marketing manager at RS Components, to increase the capabilities of design teams. DesignSpark Mechanical Add-on Modules work with SolidWorks, Catia or ProEngineer software, while ECAD Part Wizard makes it possible to use the same component models across DesignSparkPCB, Mentor Graphics, Altium, Cadence and Zuken tools.

Mouser Electronics has also released its own online simulation tool, MultiSIM Blue, the Component Evaluator Mouser Edition. The SPICE simulation online tool has been created in collaboration with automated test company National Instruments to provide integrated PCB layout as well as a bill of materials. The latter lists analogue, mixed signal ICs, passives and discretes and electromechanical parts from the distributor’s portfolio.

Online tools from silicon vendors, like WEBench (Texas Instruments) or Microchip’s MPLAB development environment, also play a role in opening up the design community. The free tools save project costs as they do not incur a licence fee for each user.

Design teams, whether hardware engineers or software developers, are using an evolved set of tools to collaborate on complex designs projects that meet budget and time-to-market demands.

Sign up to the E&T News e-mail to get great stories like this delivered to your inbox every day.

Recent articles