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Document number: BST-BMA400-DS000-13 Revision_2.2_012025

Generic Interrupt 1 and 2

The generic interrupts 1 and 2 have the exact same implementation. They are designed to detect

activity or inactivity.

The generic interrupt monitors acceleration change with respect to a reference, or in other words, the

difference between actual acceleration and reference is calculated and compared against a threshold.

The comparison is de-noised using a hysteresis.

The generic interrupt is triggered when the above mentioned difference lasts for a minimum time.

Reference, threshold, hysteresis and duration are configurable.

Both generic interrupts work the same way, but have separate sets of registers to be processed

independently of each other.

•

Generic interrupt 1 is enabled by ‘INT_CONFIG0.gen1_int_en = 1’

•

Generic interrupt 2 is enabled by ‘INT_CONFIG0.gen2_int_en = 1’

The generic interrupt supports selectable acceleration axes for evaluation:

GEN(1/2)INT_CONFIG0.act_(x/y/z)_en.

GEN(1/2)INT_CONFIG1.comb_sel selects if the interrupt shall be based on an AND (comb_sel = 1) or

an OR (comb_sel = 0) combination of all enabled axes.

The acceleration data source is selectable between acceleration from acc_filt1 or acc_filt2 by setting

GEN1/2INT_CONFIG0.data_src (0: acc_filt1, 1:acc_filt2).

The data rate for the filter output must be 100Hz. Using acc_filt2 is recommended. In this case acc_filt1

can be used independently from the interrupt engine for the data output registers and the FIFO.

GEN(1/2)INT_CONFIG0.data_src

Source for generic interrupt data

acc_filt1

acc_filt2

The mentioned reference can be static (user defined) or it can be updated dynamically.

The reference acceleration registers support reference update modes after comparison evaluation has

been done. The mode is set in GEN(1/2)INT_CONFIG0.act_refu

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