AN4650 datasheet(71/102 Pages) STMICROELECTRONICS

71 / 102 page

DocID027415 Rev 1

71/102

AN4650

Mode 3 - Auxiliary SPI mode

102

Mode 3 - Auxiliary SPI mode

The Auxiliary SPI mode (Mode 3) allows accessing the LSM6DS3 from multiple external

devices: when this mode is enabled, both an I2C slave interface and an auxiliary SPI (3-

wire) interface are available for connecting external devices.

It can be used, for example, in Electrical Image Stabilization (EIS) applications to access the

device from both the application processor and the EIS controller at the same time. The EIS

controller continuously gets the sensor data at a high rate for its image stabilization

algorithms.

7.1

Auxiliary SPI mode description

In order to enable the Auxiliary SPI mode (Mode 3), the MODE3_EN bit of the CTRL4_C

indicated in Table 52.

The external master devices have to be connected to the LSM6DS3 as illustrated in

Figure 23.

Figure 23. External controller connection in Mode 3

Table 52. Mode 3 pin description

Mode 3 function

I2C slave

inteface

SDO/SA0

I2C least significant bit of the device address (SA0)

SCL

I2C serial clock (SCL)

SDA

I2C serial data(SDA)

Auxiliary

SPI 3-wire slave

interface

SDx

Auxiliary SPI 3-wire interface serial data input (SDI) and

serial data output (SDO)

SCx

Auxiliary SPI 3-wire interface serial port clock (SPC)

OCS

Auxiliary SPI 3-wire enable

AN4650 Datasheet(PDF) 71 Page - STMicroelectronics