Platform for embedded control - Embedded.com

Platform for embedded control

STMicroelectronics' FIVE embedded controller platform, integrates the benefits of microcontrollers, together with a dedicated architecture, the 'Decision Processor', optimised for high-level algorithms and a visual programming approach.

The family of Intelligent Controller Units (ICU) based on FIVE platform unite two key concepts: a hardware architecture that combines a powerful microcontroller with a patented Decision Processor that accelerates the sophisticated algorithms that are being increasingly needed in embedded applications, and advanced visual programming tools that minimize product development time and allow product proliferation and evolution to be accomplished quickly and robustly.

Each ICU device contains a high performance 8-bit register file-based CPU, analog and digital peripherals, non-volatile memory (EPROM, EEPROM or Flash) and the Decision Processor.

The ST408 devices offer 55 instructions, including hardware multiply and divide, and deliver 2MIPS performance, while the ST508 range features an enhanced instruction set (105 instructions), 4MIPS performance and on-chip memories up to 32Kbytes of Flash or EPROM/OTP, 512bytes of RAM and 4Kbytes of data EEPROM.

Also within the 508 family, a range of devices will be available for 2V supply systems, making this family suitable for battery-powered devices, such as remote controls, mobile computing and PDAs.

The integrated Decision Processor provides hardware acceleration of decision-making algorithms, based on 'IF…THEN' rules and works in tandem with the controller. In this way, designers can take advantage of the efficiency supported by the 'intelligent algorithms' methodology while retaining full control over critical issues such as code density and real-time performance.

FIVE ICU register file architecture results in shorter computational times compared to traditional accumulator-based architectures, while the hardware multiplication and division operations allow complex calculations to be performed at speed with optimized code size.

Both the FIVE408 and FIVE508 families include analog/digital peripheral options that includes A/D converters (8 and 10-bit resolution), watchdog, power-on and brown-out detectors for power management, serial communications interfaces (SCI, SPI, I2C) and up to three 8- or 16-bit timers with 16-bit prescaler, that can be synchronized to drive AC three phase motors and that also provide PWM modulation.

Also included is an 8-bit triac driver to directly drive power devices in all key working modes:* Burst (thermal and lighting applications), * Phase Angle Partialization (universal, * AC monophase motor and inductive load control), and PWM modulation.

All FIVE 408 and FIVE 508 devices incorporate power saving and memory readout protection mechanisms.In addition, the on-board Flash memory available in the ST508 devices allows both in situ programming (ISP), where the ICU's memory can be programmed after the chip has been mounted on the final application board, and in application programming (IAP), which allows the program or data code to be modified while the application is running. This is particularly useful in applications where the control system must be able to adapt to parameters drifts or to user characteristics e.g. consumption habits or voice recognition applications.

Complementing the optimized hardware line-up, the Visual FIVE IDE development tool provides a powerful visual/graphical approach that allows high-level programming and upward compatibility among FIVE families.

Software development time is reduced because no expertise in C or assembler is required. Pin and peripheral configuration can be fully described graphically so that the software is developed as a flow chart of graphical blocks. This allows the designer to focus on the application and facilitates fast tuning of projects.

The integrated environment includes a debugger and a programmer, enabling the downloading of the project into FIVE memory by simply connecting the programming board to the PC parallel port. To ensure maximum flexibility in programming options, the FIVE software tool suite supports both C or assembler code insertion within the Visual FIVE environment and stand-alone C compiler and assembler.

“Our aim in developing the FIVE platform was to abolish the traditional division between cost-efficiency and flexibility,” said Antonino Milazzotto, business unit director. “The complete integration of hardware and software in the FIVE products, coupled with the very wide product range and aggressive roadmap, allows designers to optimize their binary code without sacrificing either the time-to-market benefits of high level language programming or their flexibility in responding to market changes.”

There will be 57 devices available in the FIVE 408 OTP family with another 190 devices available in the FIVE 508 Flash/EPROM family during this year. The FIVE 532 is a 32bit ICU that is supported by the VisualFIVE graphical development tool.

Hardware, software and application support

The Visual FIVE software development tool provides a way to program ST FIVE ICUs, in a Windows environment. The visual and graphical approach reduces assembler code writing and enables designers to focus on control and system problems.The whole project is developed as a flow chart of various blocks for peripherals start/stop, subroutines, Decision Processor algorithms, C and assembler parts.

The debugger allows full chip emulation, including peripherals and interrupts and provides a graphical plot window. The programmer downloads the project code through the programming board into ST FIVE memory, both for OTP and erasable versions.

The FSASM assembler editor is included in Visual FIVE installation to allow project development or re-editing in assembler.

A stand alone C compiler from Raisonance is for use with the FIVE 508 ICUs family .

An adaptive fuzzy modeller software tool supports design of fuzzy models and algorithms. A neuro-fuzzy architecture enables generation of the fuzzy rules. If a set of input/output measures of the system to be modelled is available, AFM provides the fuzzy parameters automatically (shape and position of antecedents membership functions and consequents values) and builds an optimized number of rules for your system. The AFM fuzzy project can be exported to VisualFIVE, MATLAB and C code.

A number of board kits or demonstrators are available for a range of motor control applications. The board kits PCB (gerber and pdf files) can be downloaded free.

Downloads are also available with examples of how to use the 408, these include programming the A/D converters and timers as well arithemetic examples, creating a sound, managing an encoder for speed control and phase angle partialization.

Published Emebedded Systems (Europe) June 2002

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