A hierarchical test scheme for system-on-chip designs

System-on-chip (SOC) design methodology is becoming the trend in the IC industry. Integrating reusable cores from multiple sources is essential in SOC design, and different design-for-testability methodologies are usually required for testing different cores. Another issue is test integration. The purpose of this paper is to present a hierarchical test scheme for SOC with heterogeneous core test anti lest access methods. A hierarchical test manager (HTM) is proposed to generate the control signals for these cores, taking into account the IEEE P1500 Standard proposal. A standard memory BIST interface is also presented, linking the HTM and the memory BIST circuit. It can control the BIST circuit with the serial or parallel test access mechanism. The hierarchical test control scheme has low area anti pin overhead, and high flexibility. An industrial case using this scheme has been designed, showing an area overhead of only about 0.63%.