fido has a unique architecture that incorporates an “RTOS Kernel in a Chip”. The fido Context Manager carries out these RTOS Kernel functions and is built right into the silicon. The Context Manager performs all of the following functions: scheduling, priority control, context switching, memory protection, timer control and management of five concurrent Hardware Contexts. No other microcontroller on the market today can do this.
The five Hardware Contexts on the chip itself enabling it to manage five distinct tasks without requiring the services of an RTOS. This means that up to five interrupt-driven or timer-driven events can be handled deterministically entirely within the silicon. More than five threads can be handled by putting multiple software threads into some Hardware Contexts. The benefits of the fido “RTOS Kernel in a Chip” approach are:
An on-chip priority-based preemptive scheduler manages context execution automatically with no software overhead
Context switching is deterministic and can be accomplished in a single clock cycle
Priority control is unified and priorities are assigned to interrupts, contexts and even DMA, peripheral I/O data transfers and external bus masters – a high priority context will interrupt a lower priority DMA transfer with no software overhead or jitter
Context timers ensure that threads are exited whenever a task takes too long or gets locked up – preventing system crashes
On-chip memory protection ensures that one thread cannot step on the protected memory space of another – code changes in one task cannot corrupt previously tested threads
Fail-safe capabilities that are impossible with an RTOS are now available - a fatal fault (such as a double bus fault) will stop only the affected context and is reported to the supervisor context – there is no interruption of other tasks and the supervisor context can correct the error
