An automotive MP-SoC featuring an advanced embedded instrument infrastructure for high dependability

In safety-critical systems, many-processor Systems-on-Chip are being increasingly employed. An example is an imminent collision detection System-on-Chip for cars. Such a system requires zero downtime and a very high reliability despite aging issues under harsh environmental conditions. By monitoring the health status of processor cores and other IPs, and taking appropriate counteractions if required, we accomplished this goal via IJTAG compatible embedded instruments. This paper shows the design of the required IJTAG network, and a number of new IJTAG-compatible embedded instruments like slack-delay, power-supply current IDDT and Intermittent Resistive Fault monitors. In addition, we discuss their numbers and optimal locations in a processor core and provide a PDL description for one of our embedded instruments. In the case of for instance a four-processor implementation, requiring only two for actual data processing, the lifetime can increase by a factor of roughly three.