April 22nd, 2013 by
By Andy The
The reason why it can be yes in both cases is because it depends on your specific definition of hard real-time.
If your definition of hard real-time means that the interrupt jitter or latency has to be less and 10 microseconds, then WinCE is not a hard real-time OS under this definition. If your hard real-time definition allows for 50-100 microseconds of jitter or latency, then WinCE can be considered a hard real-time OS.
Typically WinCE can have interrupt latencies that vary between 50-100 microseconds. In some applications that require periodic interrupts in the millisecond range then this can be quite acceptable. However, for applications that require periodic interrupts in the 1-100 microsecond range, WinCE will fail miserably under these circumstances. The interrupt latency with WinCE is just too large and it will cause interrupts to be missed.
I should also mention that WinCE is not the only Windows based real-time operating system. Standard Windows and Windows Embedded can also be used as real-time operating systems thanks to real-time 3rd party add-ons like IntervalZero’s RTX.