CheckerCore: enhancing an FPGA soft core to capture worst-case execution times

Embedded processors have become increasingly complex, resulting in variable execution behavior and reduced timing predictability. On such processors, safe timing specifications expressed as bounds on the worst-case execution time (WCET) are generally too loose due to conservative assumptions about complex architectural features, timing anomalies and programmatic complexities. Hence, exploiting the latest architectures may not be an option for embedded systems with hard real-time constraints where deadline misses cannot be tolerated. This work addresses these shortcomings by contributing CheckerCore. CheckerCore is a mode-enhanced SPARC v8 soft core processor synthesized on an FPGA. During regular execution the core adheres to its original specifications. But when operating in a special time-checking configuration, CheckerCore executes programs irrespective of inputs and steers execution along selected control flow paths. Such execution allows systematic derivation of worst-case ex...

• Type: Conference
• Year: 2009
• Where: CASES
• Authors: Jin Ouyang, Raghuveer Raghavendra, Sibin Mohan, Tao Zhang, Yuan Xie, Frank Mueller
• Keywords: Accurate Wcet Bounds, CASES 2009, Communications, Variable Execution Behavior, Worst-case Execution Time