In a deployed system containing the SEM IP core, the configuration memory system activity is a mix of reads and writes during the SEM IP core initialization state. Afterward the activity is 100% reads during the observation state to perpetually scan the configuration memory for single event upsets. Given the exceptionally low upset rate of the Xilinx configuration memory in a terrestrial environment (that is, mean time between upset is decades at sea level in NYC), the SEM IP core rarely transitions out of the Observation state into the Correction state during which writes can take place.
Continual validation of a system containing the SEM IP core should use a representative SEM IP core workload to ensure validation results will be representative of the system in deployment. Provided the system provisions the SEM IP core to complete the Initialization and enter the Observation state, the default workload of configuration memory scanning with no upsets is not only the easiest, but also representative for validation.
If desired, the SEM IP core error injection feature can be used to incorporate an occasional error detection and correction into the workload.
IMPORTANT: Xilinx does not recommend "stress testing" with high rate error injection to generate a large number of error detection and correction events, as this stimulus is unnatural and can yield validation results that are irrelevant to reliable operation of the system.
Continual validation of the system should extend beyond the research and development phase into production testing. With the SEM IP core, this requires little to no additional effort, as the system provisioning during production testing need to only enable the SEM IP core.