If you design motor-control equipment, you should examine the XMOS Semiconductor motor-control kit that comprises a brushless DC (BLDC) motor, a motor-control hardware board (2-motor control), and communication interfaces. Two XS1-L1 XCore processors implement a hard real-time, multi-threaded architecture. One XS1-L1 processor handles three-phase BLDC motor control loops and a second processor takes care of communication, logging, and motion control.
A set of control, processing, and interfacing functions help designers quickly develop advanced motor drives entirely in a high-level programming language. Find the XMOS motor-control Web site at: http://www.xmos.com/motor. The company expects to have the motor-control kit available in December 2010. See kit contents information below.
To read the white paper, “New Options for Real-Time Motor Control,” visit: https://www.xmos.com/download/public/XM-000414-WP-1.pdf. For more kit information, visit: https://www.xmos.com/download/public/XM-000417-DS-2.pdf.
The XMOS approach needs some explanation. XMOS supplies multi-core microcontrollers with as many as four XCores in a package. These cores look like general-purpose processors as well as programmable state machines tightly coupled with their own registers, memory and I/O ports as well as an XLink “bus” that communicates with other XCores on the same or external ICs. An XCore can simultaneously execute eight threads.
The company provides the XC language that includes the same operators and data types available in ANSI C. In addition, XC-language commands control I/O ports and send messages between XCore via XLink channels. You need not worry about synchronous operations and operating systems. An “operating system” exists in the hardware and an OS call on most other systems becomes an instruction or two for an XCore.
Motor-control designs rely on real-time control loops, so engineers can use the XMOS XTA static timing-analysis tool to accurately predicts performance of time-critical programs. The XTA tool comes with the free XMOS Development Tools you can download at: http://www.xmos.com/technology/design-tools. Trying the tools and reviewing sample code gives you a better understanding of what the XC language extensions can accomplish.
The XMOS Motor Control Board provides:
* Two XMOS XS1-L processors:
* Two-channel Hall-effect encoder inputs
* Isolated power section (24V at 10A max)
* 7.7 Watt Faulhaber BLDC 24v motor
* 32 Mbytes of SDRAM
* General-purpose I/O ports, a 12-channel, 10 bit ADC, Ethernet, CAN, and LCD
* Power supply
* Demonstration software and documentation
XMOS has implemented interesting capabilities in its multicore processors that remove the need for an overarching operating system. The processor architecture deserves a look by anyone who might need several processors in control applications. –Jon Titus