AN2335 datasheet(27/40 Pages) STMICROELECTRONICS

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AN2335

Free-Fall and Wake-Up Registers

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Figure 12.

DCRM bit function

8.5

FF_WU_DURATION_1 (33h)

Set the minimum duration of the free-fall, wake-up event that must be recognized by the

LIS302DL..

D7, D0 define the minimum duration of the programmed inertial event such as Free-Fall and

Wake-Up that must be recognized by the device. Duration step and maximum value depend

on the ODR chosen. For an output data rate of 400 Hz the register allows to set a duration

spanning from 0 to 637.5 msec with steps of 2.5 msec. Conversely when the output data

rate is set to 100 Hz it is possible to define an event duration spanning from 0 to 2.55 sec at

steps of 10 msec. The counter used to implement duration function is blocked when the LIR

bit in the configuration register is set to one and the interrupt event has occurred.

FreeFall event

Counter value

Duration THS

FreeFall Interrupt

FreeFall event

Counter value

Duration THS

FreeFall Interrupt

FreeFall event

Counter value

Duration THS

FreeFall Interrupt

Duration

D7, D0

Duration value. Default value: 0000 0000

AN2335 Datasheet(PDF) 27 Page - STMicroelectronics