Scalable reset domain crossing (RDC) verification using hierarchical data models

As SoC sizes increase, flat reset domain crossing verification (RDC) becomes infeasible. What’s needed is a distributed RDC verification mechanism, where each module can be verified separately and then integrated for complete verification. This paper presents a complete and accurate RDC verification approach based on a hierarchical data model that captures IP RDC intent for seamless integration wherever that IP is reused.

Requirements for accurate hierarchical RDC verification

RDC verification itself poses some unique challenges, because of which there is a need for hierarchical methodology dedicated to RDC verification. The proposed methodology should be able to accurately verify and detect following problems for an IPs and also for large
scale integrated SoC:

1. Correctness of the Reset Tree
2. Reset usage in the design

   * Do the asynchronous resets have synchronizers?

   * Are there data paths crossing reset domains?

   * Are the reset domain crossings metastability safe?

A SoC comprises of multiple IP level blocks which are developed and verified independently across multiple teams and geographies. Typically a SoC verification engineer integrates multiple IP blocks and focuses on the integration and issues in the top level. Block level verification is not required during SoC integrations as the blocks are already verified independently as part of the block level signoff. Hence, flat RDC verification on a SoC is redundant and time consuming. The requirement here is of a hierarchical methodology that can check for block integration issues and detect RDC issues across block level interfaces leading to faster RDC verification closure.