A distributed AXI-based platform for post-silicon validation

With a significant increase in the design complexity of cores and associated communication among them, post-silicon validation has become a demanding task in System on Chips (SoCs) design. To ensure that final products are fault-free and ready for market, the post-silicon validation goal is to catch bugs and pinpoint the root causes of errors that could escape from pre-silicon verification tools. Post-silicon validation involves running a hardware prototype in an environment that is similar to its final platform with its expected workload. As new SoCs tend to have many cores, the interactions among these cores are becoming so complex that post-silicon debug techniques should address not only validation of the functional aspects of a design but such techniques have to “bulletproof” the communication and synchronization among cores inside an SoC. In this paper, we propose an AXI based environment for post-silicon validation. The proposed environment involves Local Debugging Unit (LDU) and Shared Debugging Unit (SDU). LDU monitors trace of transactions issued by the hardware prototype and detect undesired conditions on bus. SDU combines debug traces from different LDUs. We embed the proposed SDU inside an AXI configurable interconnect. Major benefits of using our proposed debug platform over traditional techniques for silicon validation are as follows: 1) it detects and bypasses real time severe faulty conditions such as deadlocks resulting from design errors or electrical faults 2) there is no need for internal trace memory because SDU can communicate to the external memory through slave ports 3) it enables online monitoring of the trace buffer.