User's Manual

UMXXX
mode, or the step counter is disabled or re-initialized. The step counter can be reset
explicitly by the user application.
• Significant motion detection: this function generates an interrupt when there is a
change in user location, computed by integrating accelerometer data.
• Relative tilt detection: this function generates an interrupt when there is a change
in the tilt of the device. The interrupt is generated when the change in tilt exceeds
35 degrees. The reference start position is set when the detection logic is enabled
and it is reset when the interrupt is generated. The detection logic requires a 2
second settling time after it is enabled or re-initialized.
LSM6DSO FINITE STATE MACHINES
The LSM6DSO can have up to 16 FSM running concurrently. Each FSM is composed by a
sequence of instructions where each instruction is an immediate action (parameter setting,
interrupt generation, etc) or a RESET-NEXT condition. If the reset condition is satisfied, the
FSM goes back to the programmed reset point; if the next condition is satisfied, the FSM
moves to the next instruction; otherwise the RESET- NEXT conditions are re-tested. Each
FSM can be configured independently. FSM data can be one of the following:
accelerometer, gyroscope, integrated gyroscope or external sensor data. Data can be
decimated. Data vector is made of X, Y, Z values and a vector norm V (square root of sum
of squares). Each FSM has 3 different 8-bit masks to enable tests on positive and negative
values of X, Y, Z and V; also, each FSM has 3 different thresholds and 1 programmable
hysteresis value which is automatically added or subtracted to the selected threshold based
on the test condition; finally, each FSM has 4 different counters/timers to manage events’
durations.
LSM6DSO SMART FIFO BUFFER
The LSM6DSO accelerometer has a first-in first-out data buffer (FIFO) which can store up
to 3KB of data: 512 words of 7 bytes each; the first byte is a tag followed by six bytes of
data. The tag in the word drives the decoding. The tag includes a parity bit for validation.
The data source can be any combination of the following: the accelerometer, gyroscope,
up to 4 external sensors, embedded temperature sensor, timestamp counter and the
pedometer step counter. The data rates can be set independently for each source.
For the accelerometer: the user can choose to store high-pass filtered data, the output of
the slope detection filter, low-pass filtered data or unfiltered data summed with an optional
and programmable offset (independent for each axis); the low/high-pass filters are
configurable.
For the gyroscope: the user can choose to enable a first optional high-pass filter, and a
second optional and programmable low-pass filter.