Appendix A. Performance DataGFK-2222AD April 2018 261A-2 Instruction TimingA-2.1 OverviewThe tables in this section list the execution and incremental times in microseconds (μs) for each functionsupported by the PACSystems CPUs. Two execution times are shown for each instruction.Execution Time DescriptionEnabled Time in μs required to execute the function or function block when power flowsinto the function with valid inputs.Disabled Time in μs required to execute the function when it is not enabled.Notes:▪ All times represent typical execution time. Times may vary with input and error conditions.▪ Enabled time is for single length units of word-oriented memory.▪ COMMREQ time was measured between CPU and Ethernet module with NOWAIT option.▪ DOIO time was measured using a discrete output module.▪ Timers are updated each time they are encountered in the logic by the amount of time consumed bythe last sweep.▪ Performance times for the BUS_ functions were measured on the RX7i using a Series 90-70 GeniusBus Controller, and on the RX3i using an RMX128 Redundancy Memory Xchange Module.▪ Performance times for all redundancy (CRE and CRU) CPUs were measured with ECC enabled.▪ Due to a change in caching, measured times for some instructions changed for release 6.0 ascompared to releases 5.0/5.1. It was found that increases in some instructions were offset bydecreases in other instructions, so that no effective net change was observed.
