Replace Real-Time Hardware with Multi-Core Software
Control systems that manage many degrees of motion and require hard real-time responsiveness have traditionally relied on digital signal processors (DSPs) or field programmable gate arrays (FPGAs) to meet precision and performance requirements. Today, that model is under scrutiny as OEMs face intense pressure to cut their costs, improve quality, and differentiate products. OEMs can meet these goals by moving to a multi-core, software-based control architecture. This innovative approach is enabled by IntervalZero* RTX* 2011, a unique solution that integrates real-time symmetric multiprocessing (SMP) into Microsoft* Windows*.
Playing an important role in this transition to software-based control is the new 2nd generation Intel® Core™ processor family. These processors introduce a new microarchitecture that features Intel® Advanced Vector Extensions (Intel® AVX), a fully integrated advanced graphics engine, an innovative ring interconnect, and other enhancements. These advances enable the new processor to handle greater workloads within the same thermal envelope as the previous generation processors, and make it easier for OEMs to achieve power, cost, performance, and footprint objectives.
This article will discuss the advantages of using the IntervalZero RTX 2011 real-time plug-in and 2nd Generation Intel® Core™ processors to implement software-based control.
A New Breakthrough in Hard Real-Time Design for Complex Systems
High-performance motion-control systems are facing a host of challenges. OEMs are under constant pressure to produce systems with greater performance and more sophisticated features. In addition, OEMs are now expected to create advanced human-machine interfaces (HMIs) with slick graphics and intuitive touch-based interaction. At the same time, greater competition is leading to a faster pace of innovation and increased cost and time-to-market (TTM) pressure.
Software-based control delivers four major advantages that help OEMs overcome these challenges:
- Streamlined development process with a single tool flow
- Easier code re-use and performance scaling through the use of SMP
- Cost savings from the integration of real-time control functions and HMI on commercial off-the-shelf (COTS) hardware
- Reduced inventory and simplified quality control
Cost Savings Through Integration
Motion control systems that combine complex control and sophisticated HMIs have often relied on a two-tier architecture. The real-time applications ran on DSPs or FPGAs, while the HMI ran on a microprocessor. This meant two chip sets, two tool chains, two code bases, two development groups, and two maintenance efforts. The real-time team was often hardware-oriented, with a design process far different from the HMI team. Success required careful coordination and communications.
With RTX 2011, OEMs can implement both the hard real-time control and complex HMI on 2nd generation Intel Core processors, eliminating the need for DSPs and FPGAs. As illustrated in Figure 1, RTX 2011 makes this possible by integrating hard real-time SMP extensions into the Microsoft Windows platform. The real-time extensions serve as an RTOS, adding a real-time scheduler and other functionality to allow threads that required determinism to run in a real-time container outside the constraints of Microsoft* Windows*. At the same time, developers retain full access to the world-class HMI features available in Microsoft Windows, as well as its excellent connectivity to back-office IT systems.
Figure 1. RTX 2011 adds hard-real-time extensions to Microsoft* Windows* that use enable both HMI and control to run on 2nd generation Intel® Core™ processors
(Click on image to enlarge)
The breakthrough opportunity here is having a single integrated development environment. RTX 2011 integrates seamlessly into the Microsoft Visual Studio Integrated Development Environment, giving developers a unified platform for HMI and control development. This approach significantly simplifies and streamlines the development process. The engineering teams speak the same language so communications and coordination are easier. The result is improved quality, substantial development cost savings, and faster TTM.
The integrated approach also produces substantial benefits for the hardware design. By consolidating functionality onto 2nd generation Intel Core processors, OEMs can significantly reduce bill of materials (BOM). What’s more, developers can take advantage of COTS hardware solutions to speed development and reduce costs. Moving control logic into software also reduces inventory costs and simplifies quality control because OEMs no longer need to maintain a supply of specialized control hardware.
Improved Scalability and Re-use Through SMP
As an SMP solution, RTX 2011 has important and distinctive advantages. In an SMP system, all of the cores are controlled by a single OS instance so that any core can work on any task. Through proper OS support, SMP systems readily move tasks between cores to balance the workload efficiently.
From an OEM perspective, one big advantage of this solution is that it is easier to scale. Once developers have distributed a workload into multiple threads, performance can be increased by adding more cores (e.g., by moving from a dual-core to a quad-core processor). Or, if an OEM wants to add whole new classes of tasks to a system, the OEM can add more cores and have the new tasks run next to the original design. This flexibility leads to a “build once, deliver many” model where a single software architecture can be deployed across a range of products. Compare this model to the traditional hardware-centric approach, which requires custom DSP or FPGA designs for each new design (Figure 2).
Figure 2. Software-based control enables OEMs to re-use software across multiple products, rather than designing custom hardware each time.
(Click on image to enlarge)
SMP also offers advantages for software development. In true SMP fashion, RTX 2011 gives clear visibility across all of the cores assigned to real-time processes, along with unobstructed access to the I/O. There is no need for the complex inter-processor communications (IPC), and a single debugger can reveal the full system state. These factors significantly simplify SMP software development. By sharing resources, SMP systems can also deliver fewer interrupts, minimization of jitter, and improved performance and control.
RTX 2011 can also make use of processor resources that would otherwise go unused. For example, if the HMI is running on a quad-core 2nd generation Intel Core processor, it is unlikely that the HMI will fully load that processor. By consolidating the HMI and control algorithms on the same processor, the processor will be more fully utilized, resulting in a more efficient design (Figure 3). In addition, sharing data among the cores as well as between the two subsystems (Windows and real-time SMP) can reduce the amount of system memory needed and lowers system cost.
Figure 3. SMP helps OEMs make more efficient use of their hardware by loading each core with essential work.
(Click on image to enlarge)
Taking Advantage of 2nd Generation Intel® Core™ Processor Performance Gains
High-performance motion-control algorithms are computationally intensive, often involving matrix arithmetic such as matrix multiplication and inversion. In the past, this high-speed math required a DSP or FPGA. Today, however, the 2nd generation Intel Core processor family is powerfully equipped to handle matrix math. This new processor introduces Intel® AVX, an advanced form of Intel® Streaming SIMD Extensions (Intel® SSE) that doubles the peak floating-point performance. Intel AVX widens the data path from 128 bits to 256 bits, increases the number of operands from two to three, and includes advanced data rearrangement functions such as mask loads and data permutes. Intel AVX also increases register efficiency and use of parallel loads, reduces code size, and cuts the latency of many instructions to a single cycle. Using Intel AVX enables OEMs to tap the latest Intel® processor performance boosts, decrease overall power, and reduce component count by jettisoning dedicated DSPs and FPGAs.
Another architectural improvement, Intel’s innovative ring interconnect, delivers improved data bandwidth, performance, and power efficiency. A scalable, high-bandwidth on-die interconnect, this innovation enables high-speed, low-latency communication between the processor cores, processor graphics, and other integrated components such as the memory and display controllers. This design ensures the low-interrupt latencies required for real-time control loops. Memory performance is further increased by a doubling in memory load ports, which enables the 2nd generation Intel Core processor family to execute more instructions per clock cycle (IPC) and keep the processor fed with data.
2nd generation Intel Core processors also incorporate an advanced graphics processing unit (GPU) and memory controller (display, I/O and memory controller), all on the same piece of 32 nm silicon. The GPU built into these processors enables embedded systems to deliver sophisticated HMIs without the BOM or board space worries that accompany a graphics card. This is an important consideration for systems with advanced HMIs.
Revolutionize Your Motion Control Products
IntervalZero’s SMP-enabled RTX 2011 offers OEMs an excellent way to take full advantage of the performance gains, efficiencies, and scalability of software-based control. Teamed with Microsoft Windows and 2nd generation Intel Core processors, this solution can provide significant cost, productivity and quality improvements for a new generation of motion control devices.
For more on building interoperable solutions, see http://embedded.communities.intel.com/docs/DOC-6850
IntervalZero, Inc. is a General member of the Intel® Embedded Alliance. IntervalZero’s RTX 2011 is an essential component in an innovative new software-based control architecture that is changing the basis of competition for machine tool OEMs.
This entry was posted on Friday, March 18th, 2011 at 12:01 am and is filed under Articles. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.
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