LSM330 Datasheet, PDF (32/75 Pages) STMicroelectronics – Power-down and sleep modes

Digital interfaces
6
Digital interfaces
LSM330
The registers embedded in the LSM330 may be accessed through both the I²C and SPI
serial interfaces. The latter may be SW configured to operate either in 3-wire or 4-wire
interface mode.
To select/exploit the I²C interface, the CS line must be tied high (i.e. connected to Vdd_IO).
Pin name
CS_A
CS_G
SCL_A/G
SDA_A/G
SDO_A
SDO_G
Table 9. Serial interface pin description
Pin description
Linear acceleration SPI enable
Linear acceleration I²C/SPI mode selection (1: I²C mode; 0: SPI enabled)
Angular rate SPI enable
Angular rate I²C/SPI mode selection (1: I²C mode; 0: SPI enabled)
I²C serial clock (SCL)
SPI serial port clock (SPC)
I²C serial data (SDA)
SPI serial data input (SDI)
3-wire interface serial data output (SDO)
I²C least significant bit of the device address (SA0)
SPI serial data output (SDO)
6.1
I²C serial interface
The LSM330 I²C is a bus slave. The I²C is employed to write the data to the registers,
whose content can also be read back.
The relevant I²C terminology is provided in the table below.
Term
Transmitter
Receiver
Master
Slave
Table 10. Serial interface pin description
Description
The device which sends data to the bus
The device which receives data from the bus
The device which initiates a transfer, generates clock signals and terminates a
transfer
The device addressed by the master
There are two signals associated with the I²C bus: the Serial Clock Line (SCL) and the
Serial Data line (SDA). The latter is a bidirectional line used for sending and receiving the
data to/from the interface.
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