The System-on-Chip revolution has not impacted the field of safety-critical systems as widely as the rest of the electronics market. However, it is nowadays acknowledged that sharing resources between applications of different criticality is a key leverage to reduce costs and improve performance. Certification of systems hosting such mixed-criticality application sets requires sufficient isolation between criticality levels, i.e. a low-critical task must not cause a fault in a high-critical task, especially a temporal fault, which is likely when several co-running tasks compete for a shared resource. This digest describes implementation schemes which can be included, at both hardware and software levels, in mixed-critical systems to enforce such isolation.