An Access Mechanism for Embedded Sensors in Modern SoCs

Abstract

With technology scaling, the number of sensors integrated into modern system-on-chip (SoC) designs has increased greatly over the past several years. These sensors must be accessed for a number of reasons (test, configuration, calibration, etc.). This paper proposes a novel sensor access mechanism (SAM) to address sensor access in various operation modes, including manufacturing test mode, functional mode, built-in self-test (BIST) mode, silicon validation mode, and calibration mode. Within this mechanism, we develop a structured and scalable sensor access architecture and a pipeline sensor access flow. The SAM architecture addresses sensor insertion and access in different scenarios, while the pipeline flow is developed by utilizing the features of sensor measurement and hardware architecture to improve the efficiency of sensor access. Moreover, SAM standardizes the testing and measurement of embedded sensors by providing easy and effective access to sensors distributed across the SoC. Further, SAM is JTAG-compatible and practice-oriented for easy industry adoption. Various simulation results, collected by integrating SAM into several benchmarks, demonstrate that sensor controllability and observability can be achieved with high efficiency and low overhead using the proposed architecture.