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TimingDriftSync Class Reference

TimingDriftSync Class Reference

Inherits mbed_host_tests::BaseHostTest.


Detailed Description

This works as master-slave fashion
1) Device says its booted up and ready to run the test, wait for host to respond
2) Host sends the message to get the device current time i.e base time

#
# *
#   *                   |
#<---* DUT<- base_time  | - round_trip_base_time ------
#   *                   |                              |
# *                    -                               |
#                      -                               |
#                       |                              |
#                       |                              |
#                       | - measurement_stretch        | - nominal_time
#                       |                              |
#                       |                              |
#                      -                               |
# *                    -                               |
#   *                   |                              |
#<---* DUT <-final_time | - round_trip_final_time------
#   *                   |
# *                    -
#
#
# As we increase the measurement_stretch, the error because of transport delay diminishes.
# The values of measurement_stretch is propotional to round_trip_base_time(transport delays)
# by factor time_measurement_multiplier.This multiplier is used is 80 to tolerate 2 sec of
# transport delay and test time ~ 180 secs
#
# Failure in timing can occur if we are ticking too fast or we are ticking too slow, hence we have
# min_range and max_range. if we cross on either side tests would be marked fail. The range is a function of
# tolerance/acceptable drift currently its 5%.
#

Definition at line 22 of file timing_drift_auto.py.