2020-05-26 14:35:43 +02:00
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## About
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This applications is meant to determine RTT_MIN_OFFSET for a specific BOARD.
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The application will iteratively set an alarm starting from 0 ticks offset
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until the alarm actually triggers. Every time the alarm underflows the
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alarm will not be triggered within the expected time, so the application
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will set another one with a larger offset until the alarm successfully triggers.
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The rtt might advance between the call to rtt_get_counter() and
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rtt_set_alarm(). If that happens with val=1 then the alarm would be set
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to the current time and underflow. The test is ran over multiple samples
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to make this more likely to happen. Nonetheless its always possible
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that now sample will underflow so a conservatory value would be to
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set RTT_MIN_OFFSET to the value found out with this test + 1tick.
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## Usage
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2023-05-06 15:33:03 +02:00
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Run `BOARD=<board> make -C tests/periph/rtt_min/ flash test` the value will
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2020-05-26 14:35:43 +02:00
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be printed as:
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```
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Evaluate RTT_MIN_OFFSET over 1024 samples
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........................................................................
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........................................................................
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........................................................................
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........................................................................
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RTT_MIN_OFFSET for <board>: 2
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```
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