IIS2MDC datasheet(25/40 Pages) STMICROELECTRONICS

Part #	IIS2MDC

Description	High-accuracy, ultra-low-power, 3-axis digital output magnetometer

PDF	40 Pages

Scroll/Zoom	100%

Manufacturer	STMICROELECTRONICS [STMicroelectronics]

Direct Link	http://www.st.com

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25 / 40 page

DocID030986 Rev 1

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IIS2MDC

Digital interfaces

6.2

SPI bus interface

The IIS2MDC SPI is a bus slave. The SPI allows writing and reading the registers of the

device.

The serial interface interacts with the application using 3 wires: CS, SPC, SDI/O.

6.2.1

SPI write

Figure 6. SPI write protocol

The SPI write command is performed with 16 clock pulses. The multiple byte write

command is performed by adding blocks of 8 clock pulses to the previous one.

bit 0: WRITE bit. The value is 0.

bit 1-7: address AD(6:0). This is the address field of the indexed register.

bit 8-15: data DI(7:0) (write mode). This is the data that is written inside the device (MSb

first).

bit 16-... : data DI(...-8). Further data in multiple byte writes.

Figure 7. Multiple byte SPI write protocol (2-byte example)

SPC

SDI

D I7D I6

D I5D I4

DI3DI2

DI1DI0

AD5 AD 4 AD 3 AD2 AD 1 AD0

AD6

SPC

SDI

AD5 AD4 AD3 AD2 AD1 AD 0

DI7 D I6 DI5 D I4 DI3 DI2 DI1 DI0 DI15 D I1 4 DI13 D I1 2 DI11 DI10 DI9 DI8

AD6

IIS2MDC Datasheet(PDF) 25 Page - STMicroelectronics