LSM330 Datasheet, PDF (20/75 Pages) STMicroelectronics – Power-down and sleep modes

Functionality
4
Functionality
LSM330
The LSM330 is a system-in-package featuring a 3D digital accelerometer with two
embedded state machines and a 3D digital gyroscope, together with two FIFO memory
blocks available to manage linear acceleration and angular rate data.
The device includes specific sensing elements and two IC interfaces capable of measuring
both the acceleration and angular rate applied to the module and providing a signal to
external applications through an SPI/I²C serial interface.
The various sensing elements are manufactured using specialized micromachining
processes, while the IC interfaces are developed using CMOS technology that allows the
design of a dedicated circuit which is trimmed to better match the sensing element
characteristics.
4.1
Power modes
The linear acceleration sensor and the angular rate sensor can be either activated or
separately set in power-down/ sleep mode for applications optimized for power saving.
The acceleration sensor operating modes can be selected between normal or power-down
through CTRL_REG5_A (20h). The angular rate sensor operating mode can be selected
among normal power-down or sleep mode, through CTRL_REG1_G (20h).
4.2
4.2.1
Linear acceleration sensor digital main blocks
State machine
The LSM330 embeds two state machines able to run a user-defined program.
The program is composed of a set of instructions that defines the transition to successive
states. Conditional branches are possible.
From each state (n) it is possible to have a transition to the next state (n+1) or to a reset
state. The transition to the reset point happens when the “RESET condition” is true. The
transition to the next step happens when the “NEXT condition” is true.
An interrupt is triggered when the Output/Stop/Continue state is reached.
Each State machine allows implementing, in a flexible way, gesture recognition, free-fall,
wake-up, 4D/6D orientation, pulse counter and step recognition, click/double-click,
shake/double-shake, face-up/face-down, turn/double-turn:
– Code and parameters are loaded by the host into dedicated memory areas for the
state program
– State program with timing based on ODR or decimated time
– Possibility of conditional branches
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