CVA6-RT: an Open-Source Time-Predictable RV64 Processor for Mixed-Criticality Systems
Provides a time-predictable, open-source RV64 processor for real-time and mixed-criticality systems, addressing the need for deterministic execution in such domains.
CVA6-RT extends the open-source CVA6 RISC-V processor with real-time features (TLB partitioning, scratchpad L1 cache, low-latency interrupts) to bound worst-case latency and reduce timing variability for mixed-criticality systems. It achieves 12-cycle interrupt latency, 10x lower than baseline CVA6.
This work presents CVA6-RT, a real-time micro-architectural extension of the CVA6 core to bound worst-case latency and reduce task's timing execution variability. CVA6-RT implements the rv64gch ISA and features advanced support for real-time execution, including TLB partitioning and locking for predictable address translation, a dynamically reconfigurable scratchpad mode in the L1 caches for deterministic memory access, and low-latency interrupt handling via an enhanced interrupt controller combined with hardware-assisted context stacking. With real-time features enabled, CVA6-RT achieves an interrupt latency of 12 cycles, comparable to that of simpler Arm Cortex-M microcontrollers, and 10x lower than the baseline CVA6 core.