MLX90363 Datasheet, PDF (14/57 Pages) Melexis Microelectronic Systems – Triaxis® Magnetometer IC With High Speed Serial Interface

MLX90363
Triaxis® Magnetometer IC
With High Speed Serial Interface
14. MLX90363 Serial Interface
The MLX90363 serial interface allows a master device to operate the position sensor. The MLX90363
interface allows multi-slave applications and synchronous start of the data acquisition among the slaves.
The interface offers 2 Mbps data transfer bit rate and is full duplex. The interface accepts messages of 64
bits wide only, making the interfacing robust.
In this document, the words message, frame and packet refer to the same concept.
14.1. Electrical Layer and Timing Specification
Message transmissions start necessarily at a falling edge on /SS and end necessarily at a rising edge on
the /SS signal. This defines a message. The serial interface counts the number of transmitted bits and
declares the incoming message invalid when the bit count differs from 64. The master must therefore
ensure the flow described below:
1. Set pin /SS Low
2. Send and receive 8 bytes or four (4x) 16 bit words
3. Set pin /SS High
The MISO and MOSI signals change on SCLK rising edge and are captured on SCLK falling edge. The
most-significant-bit of the transmitted byte or word comes first ⁽²¹⁾.
/SS Pin
SCLK Pin
MOSI Pin
MISO Pin
t1
t2
tSCLK
tSCLK_HI
tSCLK_LO
tMOSI
tMISO
Figure 2 – Serial Interface Timing Diagram
t3
t4
The interface is sensitive, in Trigger mode 2 (see section 14.6), to Sync pulses. A Sync pulse is negative
pulse on /SS, while SCLK is kept quiet.
/SS (IC PIN)
tSyncPulse
Figure 3 – Sync Pulse Timing Diagram
21 _{For instance, for master compatible w/ the Motorola SPI protocol, the configuration bits must be CPHA=1, CPOL=0, LSBFE=0.}
3901090363
Rev. 005
Page 14 of 57
Data Sheet
Jul/13