Overview

Real-Time Environment (RTE) is a general-purpose commercial-off-the-shelf (COTS) computing solution that provides extremely deterministic, low-latency interrupt performance for demanding real-time applications.

RTE is comprised of hardware and software layered on commercial-off-the-shelf (COTS) platforms running the industry-standard SuSE Linux^TM operating system.  RTE is a performance extension; a simple PCI board and software extension plug into unmodified COTS hardware and Linux.

RTE can meet any high-demand real-time computing challenge, especially blazingly fast hardware-in-the-loop systems. When properly configured, RTE delivers approximately 4µsec interrupt latency, 16µsec determinism and 250nsec clock resolution.

Most modern COTS systems have approximately one nanosecond or less CPU clocks, while their native operating system (OS) software cycles at one millisecond.  This means COTS computers have operating system software one million times slower than the raw capability of their processors, rendering them impotent for serious real-time applications.

By using Symmetric Multi-Processor (SMP) systems and a technique called "hard real-time", RTE shields individual CPUs from undesirable interrupt processing and other Linux tasks.  This technique fully exploits CPU processing power without expensive, proprietary hardware or software.

RTE Hardware
The PCI Real-Time Option Module (PCI-RTOM) is the foundational RTE hardware element.  It provides key real-time features permitting precise, engineering-level system control.

Each PCI-RTOM includes programmable counter/timers, a free running counter/clock and bi-directional external interrupts.  Any of these elements can trigger internal or external interrupts, permitting RTE to launch synchronous tasks, stimulate external devices, respond to external interrupts, and synchronize with other RTE nodes or subsystems. 

PCI-RTOM Features

Six programmable countdown interval timers with 250nsec resolution: Each timer, numbered Timer 0 through Timer 5, may be individually allocated to user applications.  Frequencies range from 4MHz (250nsec) to 16 KHz (64µsec).  Each timer is programmable as single shot or repeating.

External synchronization and connectivity: Timer 0 and Timer 1 may be individually clocked from external frequency sources and synchronized across multiple systems.

Eight external interrupts: Each interrupt is programmable as an input or output, each with Interrupt Request (IRQ) and Interrupt Acknowledge (IACK) capabilities.

Real-time program control: Any external interrupt or timer event may signal a real-time "wake up" to any user program.

One 64-bit free-running counter: Read-only counter with one microsecond resolution accommodates extremely short or long events.

RTE Software
The included RTE software permits easy access to PCI-RTOM features.  It schedules real-time applications using one of its six timers or eight external interrupts.  This facilitates synchronized application control within a single system or across multiple nodes.  RTE accommodates application-timing tasks using the free-running counter, and is "SMP-safe."

The RTE Software includes:

Executive Scheduler: Intuitive, powerful, GUI-based programmer control to lock tasks and processes to memory and a CPU.  It executes processes with a priority-oriented, highly preemptive mechanism for predictable, repeatable performance

Monitor: Real-time GUI measurement tool that captures and displays critical performance parameters, including: interrupt and task determinism; frame overruns and misses; interrupt and task latency; task setup and status.  The Monitor simplifies task problem analysis and tuning for maximum application performance.

Real-Time Extensions (RTEX): Linux software extensions and PCI-RTOM driver that control the Real Time Environment.

Diagnostic: Full test capability for all software RTEX and PCI-RTOM functions.

Documentation: Comprehensive programming instructions and examples delivered on CD-ROM.

License: Unlimited use and access to all real-time PCI-RTOM features.

For detailed information about RTE, download the RTE White Paper here.