VPR: Arm and RISC-V Inter-Processor Communication

In our last post, we explored the Nordic VPR RISC-V processor through the lens of the peripheral processor (PPR) on the nRF54H20. While we demonstrated how the application processor can configure and start a VPR processor, we stopped short of demonstrating any further communication between them. Most meaningful use-cases of the PPR and the FLPR, involve communicating with the controlling processor.
Nordic uses two different hardware peripherals for inter-processor communication (IPC) on the nRF54H20: VEVIF (VPR Event Interface) and BELLBOARD.