Control Flow Checking Algorithm using Soft-basedIntra-/Inter-block Assigned-Signature

In radiation environments, alpha particles, cosmic rays and solar wind flux can cause a single event upset (SEU), which is one of the major sources of bit-flips in digital electronics. The control-flow checking is an effective way for the running systems to prevent the breaking-down caused by SEU. Control-Flow Checking by Software Signatures (CFCSS) and Enhanced Control-Flow Checking with Assertions (ECCA) are representative of pure software methods that check the control flow of a program by using assigned signatures. But these assigned-signatures algorithms cannot check for intra-block control-flow errors. To overcome this shortcoming, an Interrupt Count - Control-Flow Checking by Software Signatures (IC-CFCSS) algorithm is presented based on the CFCSS. The total number of instructions running in the basic blocks per machine cycle is calculated during the course of pre-compilation. Whether or not to jump into a given block is judged by setting up interrupt instructions through the basic block running-time. Fault-injection experiments show that the error-detection coverage is increased by the IC-CFCSS algorithm.