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tests: latency_measure: tweak frdm_k64f config

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The FRDM K64F board runs at 120 MHz and has a 24 bit timer.
According to its timer driver, its MAX_TICKS (which comes into
play for a tickless kernel) is calculated as ...
     CYC_PER_TICK = 120 MHz / ticks per second
     MAX_TICKS = (COUNTER_MAX / CYC_PER_TICK) - 1

To achieve a minimum value of MAX_TICKS=1, ticks per second must
be set to at least 15. Experimentation has shown that setting the
number of ticks per second below this threshhold on a tickless
kerenl leads to unreliable timestamps.

Signed-off-by: Peter Mitsis <peter.mitsis@intel.com>
This commit is contained in:
Peter Mitsis 2024-01-18 11:32:33 -05:00 • committed by Carles Cufí
commit 5573b20ec6
1 changed files with 4 additions and 4 deletions
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8
tests/benchmarks/latency_measure/boards/frdm_k64f.conf
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# eliminate timer interrupts during the benchmark
# for platforms that do not allow frequency dividers large enough to get
# system clock tick period in 1 sec, make system clock tick to 0.1 sec
CONFIG_SYS_CLOCK_TICKS_PER_SEC=10
# The minimum number of system ticks per second that this platform will
# allow for a tickless kernel given its 24-bit timer and its 120 MHz
# clock rate is 15.
CONFIG_SYS_CLOCK_TICKS_PER_SEC=15