  In the last decade, we have witnessed exponential growth in the complexity of
control systems for safety-critical applications (automotive, robots,
industrial automation) and their transition to heterogeneous mixed-criticality
systems (MCSs). The growth of the RISC-V ecosystem is creating a major
opportunity to develop open-source, vendor-neutral reference platforms for
safety-critical computing. We present SentryCore, a reliable, real-time,
self-contained, open-source mega-IP for advanced control functions that can be
seamlessly integrated into Systems-on-Chip, e.g., for automotive applications,
through industry-standard Advanced eXtensible Interface 4 (AXI4). SentryCore
features three embedded RISC-V processor cores in lockstep with
error-correcting code (ECC) protected data memory for reliable execution of any
safety-critical application. Context switching is accelerated to under 110
clock cycles via a RISC-V core-local interrupt controller (CLIC) and dedicated
hardware extensions, while a timer-based direct memory access (DMA) engine
streamlines sensor data readout during periodic control loops. SentryCore was
implemented in Intel's 16nm process node and tested with FreeRTOS, ThreadX, and
RTIC software support.
