LIS3MDL datasheet(16/33 Pages) STMICROELECTRONICS

16 / 33 page

Digital interfaces

LIS3MDL

16/33

DocID024204 Rev 4

Digital interfaces

The registers embedded in the LIS3MDL 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.

The serial interfaces are mapped to the same pads. To select/exploit the I2C interface, the

CS line must be tied high (i.e. connected to Vdd_IO).

5.1

I2C serial interface

The LIS3MDL I2C is a bus slave. The I2C is employed to write data to registers whose

content can also be read back.

The relevant I2C terminology is given in the table below.

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. Both lines must be connected to Vdd_IO through an external pull-up

resistor. When the bus is free, both the lines are high.

The I2C interface is compliant with fast mode (400 kHz) I2C standards, as well as with

normal mode.

When the I2C interface is used, the SDO/SA1 pin has to be connected to Vdd_IO or GND.

Table 9. Serial interface pin description

Pin name

Pin description

SPI enable

I2C/SPI mode selection (1: SPI idle mode / I2C communication enabled;

0: SPI communication mode / I2C disabled)

SCL

SPC

I2C serial clock (SCL)

SPI serial port clock (SPC)

SDA

SDI

SDO

I2C serial data (SDA)

SPI serial data input (SDI)

3-wire interface serial data output (SDO)

SA1

SDO

I2C less significant bit of the device address (SA1)

SPI serial data output (SDO)

Table 10. I2C terminology

Term

Description

Transmitter

The device which sends data to the bus

Receiver

The device which receives data from the bus

Master

The device which initiates a transfer, generates clock signals and terminates a

transfer

Slave

The device addressed by the master

LIS3MDL Datasheet(PDF) 16 Page - STMicroelectronics

LIS3MDL Datasheet(HTML) 16 Page - STMicroelectronics

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33

Datasheet Download

Link URL