Data Sheet

DocID025715 Rev 2 37/72
LSM9DS1 Digital interfaces
72
5.3.3 SPI read in 3-wire mode
3-wire mode is entered by setting the SIM bit to ‘1’ (SPI serial interface mode selection) in
CTRL_REG3_M (22h).
When 3-wire mode is used, the SDO_M pin has to be connected to GND or Vdd_IO.
Figure 27. SPI read protocol in 3-wire mode
The SPI read command is performed with 16 clock pulses:
bit 0: READ bit. The value is 1.
bit 1: MS bit. When 0, does not increment the address; when 1, increments the address in
multiple reads.
bit 2-7: address AD(5:0). This is the address field of the indexed register.
bit 8-15: data DO(7:0) (read mode). This is the data that is read from the device (MSb first).
A multiple read command is also available in 3-wire mode.
CS
SPC
SDI/O
RW
DO7DO6DO5DO4DO3DO2DO1DO0
AD5 AD 4 AD3 AD2 AD1 AD 0MS
AM10134V1
CS_M