MLX90363 Datasheet, PDF (36/57 Pages) Melexis Microelectronic Systems – Triaxis® Magnetometer IC With High Speed Serial Interface

MLX90363
Triaxis® Magnetometer IC
With High Speed Serial Interface
14.20. Start-up Sequence (Serial Communication)
The MLX90363 serial interface is enabled after the internal start-up initializations and start-up checks.
Note: The start-up sequence of the MLX90363 firmware is described at chapter 19.1.
The recommended SCI start-up sequences (Master – Slave) are depicted in the following message
sequence charts, and timing diagrams. It usually starts with a NOP SI message. Ready is the first SO
message.
For safety critical applications, Melexis recommends performing two extra checks prior to the request of
the first regular data: oscillator frequency check and a readback of the diagnostic details (ROM, RAM,
ADC Monitor…)
Message Sequence Chart
Start-up Sequence (Basic Scenario)
Message Sequence Chart
Start-up Sequence (Safety Scenario)
Master
Slave1
Master
Slave1
NOP(Challenge) ( )
Ready ()
NOP ( )
Ready ()
GETx ( )
Challenge Echo ()
Loop
GETx ( )
Regular Packet ()
OscCounterStart ( )
Challenge Echo ()
OscCounterStop ( )
OscStartAck ()
DiagDetails ( )
OscCounter ()
Loop
GETx ( )
DiagDetails ()
GETx ( )
Regular Packet ()
Figure 20 – MSCs Start-up sequence examples (basic and safety critical scenario)
VDD
POR
SI
SO
SS
NOP GETx
Ready Challenge Echo
tPOR
tStartUp
Figure 21 – Start-up sequence, basic scenario, timing diagram
VDD
POR
SI
SO
SS
NOP OscStart
Ready Challenge Echo
OscStop DiagDetails
StartAck OscCounter
GETx
DiagDetails
tPOR
tStartUp
tOscCounter
Figure 22 – Start-up sequence, safety critical scenario, timing diagram
Notes:
• The timing tStartUp is specified at chapter Timing Specifications (Section 10)
• The slave answers with NTT in case the first SI message occurs prior the end of the initial checks.
• The NOP - Challenge Echo is meant to diagnose the SCI link.
3901090363
Rev. 005
Page 36 of 57
Data Sheet
Jul/13