BSP and Device Driver Development Guide
The tm27 test from the RTEMS Timing Test Suite is designed to measure the length of time required to vector to and return from an interrupt handler. This test requires some help from the BSP to know how to cause and manipulate the interrupt source used for this measurement. The following is a list of these:
MUST_WAIT_FOR_INTERRUPT - modifies behavior of tm27.
Install_tm27_vector - installs the interrupt service
routine for the Interrupt Benchmark Test (tm27).
Cause_tm27_intr - generates the interrupt source
used in the Interrupt Benchmark Test (tm27).
Clear_tm27_intr - clears the interrupt source
used in the Interrupt Benchmark Test (tm27).
Lower_tm27_intr - lowers the interrupt mask so the
interrupt source used in the Interrupt Benchmark Test (tm27)
can generate a nested interrupt.
All members of the Timing Test Suite are designed to run WITHOUT the Clock Device Driver installed. This increases the predictability of the tests' execution as well as avoids occassionally including the overhead of a clock tick interrupt in the time reported. Because of this it is sometimes possible to use the clock tick interrupt source as the source of this test interrupt. On other architectures, it is possible to directly force an interrupt to occur.
BSP and Device Driver Development Guide
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