LSM6DSV80X datasheet(6/181 Pages) STMICROELECTRONICS

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2.5

Finite state machine

The LSM6DSV80X can be configured to generate interrupt signals activated by user-defined motion patterns. To

do this, up to 8 embedded finite state machines can be programmed independently for motion detection such as

glance gestures, absolute wrist tilt, shake and double-shake detection.

Definition of finite state machine

A state machine is a mathematical abstraction used to design logic connections. It is a behavioral model

composed of a finite number of states and transitions between states, similar to a flow chart in which one can

inspect the way logic runs when certain conditions are met. The state machine begins with a start state, goes to

different states through transitions dependent on the inputs, and can finally end in a specific state (called stop

state). The current state is determined by the past states of the system. The following figure shows a generic

state machine.

Figure 2. Generic state machine

Finite state machine in the LSM6DSV80X

The LSM6DSV80X works as a combo accelerometer-gyroscope sensor, generating acceleration and angular rate

output data. It is also possible to connect an external sensor like a magnetometer or pressure sensor by using the

sensor hub feature (mode 2). These data can be used as input of up to 8 programs in the embedded finite state

machine (Figure 3. State machine in the LSM6DSV80X ).

All 8 finite state machines are independent: each one has its dedicated memory area and it is independently

executed. An interrupt is generated when the end state is reached or when some specific command is performed.

Figure 3. State machine in the LSM6DSV80X

FSM

SIGNAL

CONDITIONING

X = 1..8

Low-g accelerometer [LSB]

Gyroscope [LSB]

LSM6DSV80X

FSM output

External sensor (magnetometer) [LSB]

(optional)

High-g accelerometer [LSB]

LSM6DSV80X

Embedded low-power features

DS14764 - Rev 1

page 6/181

LSM6DSV80X Datenblatt(PDF) 6 Page - STMicroelectronics