The ThreadX® real-time operating systems from Express Logic (San Diego, CA) have been integrated into Avidyne Corporations' DFC90 attitude-based digital flight control systems in Cirrus SR20 and SR22 aircraft. The DFC90 is an integrated flight computer and control panel designed as a slide-in replacement for existing rate-based STEC 55X flight computers. The DFC90 flight control system receives input regarding the aircraft’s attitude, heading, and altitude, as well as input from the pilot and navigation system that specify the desired attitude, heading, altitude, and rate of climb/descent. As the operating system powering Avidyne's flight control system, ThreadX controls all functions in the DFC90.

ThreadX features a boot time of 300 cycles, context switch time of 20 cycles, and semaphore get of 30 cycles. The minimal RAM requirement is 500 bytes and minimal ROM requirement is 2K bytes. The minimal kernel size is under 2K bytes, and the system features queue services of 900 bytes, semaphore services of 450 bytes, mutex services of 1200 bytes, and block memory services of 550 bytes.

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