MLX90316_05 Datasheet, PDF (21/34 Pages) List of Unclassifed Manufacturers – Rotary Position Sensor IC

MLX90316
Rotary Position Sensor IC
16. Serial Protocol
16.1. Introduction
The MLX90316 features a digital Serial Protocol mode. The MLX90316 is considered as a Slave node.
The serial protocol of the MLX90316 is a three wires protocol (/SS, SCLK, MOSI-MISO):
• /SS pin is a 5 V tolerant digital input
• SCLK pin is a 5 V tolerant digital input
• MOSI-MISO pin is a 5 V tolerant open drain digital input/output
The basic knowledge of the standard SPI specification is required for the good understanding of the
present section.
16.2. SERIAL PROTOCOL Mode
• CPHA = 1
• CPOL = 0
even clock changes are used to sample the data
active-Hi clock
The positive going edge shifts a bit to the Slave’s output stage and the negative going edge samples the
bit at the Master’s input stage.
16.3. MOSI (Master Out Slave In)
The Master sends a command to the Slave to get the angle information.
16.4. MISO (Master In Slave Out)
The MISO of the slave is an open-collector stage. Due to the capacitive load (TBD) a >1 kΩ pull-up is
used for the recessive high level (in fast mode). Note that MOSI and MISO use the same physical pin of
the MLX90316.
16.5. /SS (Slave Select)
The /SS pin enables a frame transfer (if CPHA = 1). It allows a re-synchronisation between Slave and
Master in case of communication error.
16.6. Master Start-up
/SS, SCLK, MISO can be undefined during the Master start-up as long as the Slave is re-synchronized
before the first frame transfer.
16.7. Slave Start-up
The slave start-up (after power-up, or an internal failure) takes 16 ms. Within this time /SS and SCLK is
ignored by the Slave. The first frame can therefore be sent after 16 ms. MISO is Hi-Z (i.e. Hi-impedant)
until the Slave is selected by its /SS input. MLX90316 will cope with any signal from the Master while
starting up.
3901090316
Rev. 001
Page 21 of 34
Data Sheet
4 October 05