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diff --git a/doc/supplements/hppa1_1/timedata.t b/doc/supplements/hppa1_1/timedata.t new file mode 100644 index 0000000000..a26ce419c3 --- /dev/null +++ b/doc/supplements/hppa1_1/timedata.t @@ -0,0 +1,105 @@ +@ifinfo +@node HP-7100 Timing Data, HP-7100 Timing Data Introduction, Memory Requirements RTEMS RAM Workspace Worksheet, Top +@end ifinfo +@chapter HP-7100 Timing Data +@ifinfo +@menu +* HP-7100 Timing Data Introduction:: +* HP-7100 Timing Data Hardware Platform:: +* HP-7100 Timing Data Interrupt Latency:: +* HP-7100 Timing Data Context Switch:: +* HP-7100 Timing Data Directive Times:: +@end menu +@end ifinfo + +@ifinfo +@node HP-7100 Timing Data Introduction, HP-7100 Timing Data Hardware Platform, HP-7100 Timing Data, HP-7100 Timing Data +@end ifinfo +@section Introduction + +The timing data for the PA-RISC version of RTEMS is +provided along with the target dependent aspects concerning the +gathering of the timing data. The hardware platform used to +gather the times is described to give the reader a better +understanding of each directive time provided. Also, provided +is a description of the interrupt latency and the context +switch times as they pertain to the PA-RISC version of RTEMS. + +@ifinfo +@node HP-7100 Timing Data Hardware Platform, HP-7100 Timing Data Interrupt Latency, HP-7100 Timing Data Introduction, HP-7100 Timing Data +@end ifinfo +@section Hardware Platform + +No directive execution times are reported for the +HP-7100 because the target platform was proprietary and +executions times could not be released. + +@ifinfo +@node HP-7100 Timing Data Interrupt Latency, HP-7100 Timing Data Context Switch, HP-7100 Timing Data Hardware Platform, HP-7100 Timing Data +@end ifinfo +@section Interrupt Latency + +The maximum period with traps disabled or the +processor interrupt level set to it's highest value inside RTEMS +is less than RTEMS_MAXIMUM_DISABLE_PERIOD +microseconds including the instructions which +disable and re-enable interrupts. The time required for the +HP-7100 to vector an interrupt and for the RTEMS entry overhead +before invoking the user's trap handler are a total of +RTEMS_INTR_ENTRY_RETURNS_TO_PREEMPTING_TASK +microseconds. These combine to yield a worst case interrupt +latency of less than RTEMS_MAXIMUM_DISABLE_PERIOD + +RTEMS_INTR_ENTRY_RETURNS_TO_PREEMPTING_TASK microseconds at 15 Mhz. +[NOTE: The maximum period with interrupts disabled was last +determined for Release RTEMS_RELEASE_FOR_MAXIMUM_DISABLE_PERIOD.] + +It should be noted again that the maximum period with +interrupts disabled within RTEMS for the HP-7100 is hand calculated. + +@ifinfo +@node HP-7100 Timing Data Context Switch, HP-7100 Timing Data Directive Times, HP-7100 Timing Data Interrupt Latency, HP-7100 Timing Data +@end ifinfo +@section Context Switch + +The RTEMS processor context switch time is RTEMS_NO_FP_CONTEXTS +microsections for the HP-7100 when no floating point context +switch is saved or restored. Saving and restoring the floating +point context adds additional time to the context +switch procedure. Additional execution time is required when a +TASK_SWITCH user extension is configured. The use of the +TASK_SWITCH extension is application dependent. Thus, its +execution time is not considered part of the raw context switch +time. + +Since RTEMS was designed specifically for embedded +missile applications which are floating point intensive, the +executive is optimized to avoid unnecessarily saving and +restoring the state of the numeric coprocessor. On many +processors, the state of the numeric coprocessor is only saved +when an FLOATING_POINT task is dispatched and that task was not +the last task to utilize the coprocessor. In a system with only +one FLOATING_POINT task, the state of the numeric coprocessor +will never be saved or restored. When the first FLOATING_POINT +task is dispatched, RTEMS does not need to save the current +state of the numeric coprocessor. As discussed in the Register +Usage section, on the HP-7100 the every task is considered to be +floating point registers and , as a rsule, every context switch +involves saving and restoring the state of the floating point +unit. + +The following table summarizes the context switch +times for the HP-7100 processor: + +@example +no times are available for the HP-7100 +@end example + +@ifinfo +@node HP-7100 Timing Data Directive Times, Command and Variable Index, HP-7100 Timing Data Context Switch, HP-7100 Timing Data +@end ifinfo +@section Directive Times + +No execution times are available for the HP-7100 +because the target platform was proprietary and no timing +information could be released. + |