RTEMS MIPS Applications Supplement
The maximum period with interrupts disabled within RTEMS is less than TBD microseconds including the instructions which disable and re-enable interrupts. The time required for the XXX to vector an interrupt and for the RTEMS entry overhead before invoking the user's interrupt handler are a total of 9 microseconds. These combine to yield a worst case interrupt latency of less than TBD + 9 microseconds at 20 Mhz. [NOTE: The maximum period with interrupts disabled was last determined for Release 4.0.0.]
It should be noted again that the maximum period with interrupts disabled within RTEMS is hand-timed and based upon worst case (i.e. CPU cache disabled and no instruction overlap) times for a 20 Mhz processor. The interrupt vector and entry overhead time was generated on an BSP_FOR_TIMES benchmark platform using the Multiprocessing Communications registers to generate as the interrupt source.
RTEMS MIPS Applications Supplement
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