Embedded core test generation using broadcast test architecture and netlist scrambling

In this work, based on the concept of test pattern broadcasting, we propose a new core-based testing method which gives core users the maximum level of test freedom. Instead of only using the test patterns delivered by core providers, core users are allowed to broadcast their own test patterns to the cores of a SoC (system on chip) design for parallel scan testing. The fault coverage of each core test, using test patterns developed by any core user, can be evaluated by an enhanced version of a traditional fault simulator. The netlist of each core is scrambled before it is delivered to core users, thus the netlist will not be revealed. The enhanced fault simulator of a core has the capabilities of decoding the scrambled netlist, and performing fault simulation for the test patterns provided by each of the core users. For each core, both random test patterns (applied by a core user), and golden test patterns (delivered by the core provider) jointly achieve high and flexible fault coverage requirements. The enhanced logic simulator of each core can also decrypt the scrambled netlist, and perform logic simulation with the objective of generating fault-free test responses for signature analysis (for example). The proposed method has the advantages of minimizing the number of scan pins, reducing the test application time, and achieving the maximum level of test quality control by core users. Simulation results demonstrate the feasibility of this method.