Back-door access to registers and memory locations
It is important to back-door access the registers and memory locations to verify their correct operation. Back-door access provides an alternative way to uncover hidden bugs in a design. This happens because normal write and read operations use the same path, which can unintentionally mask issues. For instance, if the wrong memory location is accessed or data bits are flipped, the error during a write operation could be reversed during the corresponding read operation, making the bug invisible.
With back-door access, you can verify registers and memory much more efficiently because it allows direct access to these components with minimal or no simulation time. This method becomes particularly useful after confirming that the physical interface of the design works correctly. At that point, back-door access can significantly reduce the time needed for configuring the device under test (DUT), which is often a time-consuming process.
Back-door access works by directly interacting with the simulation constructs of registers or memory through their hierarchical paths in the design. However, implementing it can be challenging because it requires identifying and maintaining these hierarchical paths and understanding the specific simulation constructs used in the design.