Exploiting Inactive Rename Slots for Detecting Soft Errors

Abstract

Register renaming is a widely used technique to remove false data dependencies in superscalar datapaths. Rename logic consists of a table that holds a physical register mapping for each architectural register and a logic for checking intra-group dependencies. This logic checking consists of a number of comparators that compares the values of destination and source registers. Previous research has shown that the full capacity of the dependency checking logic is not used at each cycle. In this paper we propose some techniques that make use of the unused capacity of the dependency checking logic of the rename stage in order to detect soft errors that occur on the register tags while the instructions are passing through the frontend of the processor.