MLX75031 Datasheet, PDF (62/67 Pages) Melexis Microelectronic Systems – Optical Gesture & Proximity Sensing IC

MLX75031
Optical Gesture & Proximity Sensing IC
with Integrated LED Drivers
Datasheet
8.19. Global Timing Diagrams
A global timing diagram with separate SM-RO cycles is given in Figure 21. After power-up there is a Power-
On-Reset phase (POR) to initialize the sensor into a reset state. When the device is ready to accept the first
command, the DR pin goes high. In Figure 21 the first command is the WR command to define the contents
of the user registers (optionally). The first measurement cycle is e.g. initiated by uploading a SM command.
After completion of the measurement cycle, the DR goes high. This indicates that the read-out cycle can be
started. A RO command has to be uploaded to bring the data on the MISO pin. When the read-out is
completed, a new measurement cycle can be started. In Figure 21 a SM command is used. This starts a next
measurement cycle. Once DR is high, a read-out can be done again.
In between different Measurement/Read-Out cycles, the user registers can be changed with WR
commands. Optionally those registers can be read back with the RR command to check if the right values
were uploaded.
POR
CS
SCLK
MOSI
(WR)
SM
RO
(WR)
SM
RO
MISO
Output Data
Output Data
DR
Device State
POR
Idle
SM Measurement
Idle
Read-out
Idle
SM Measurement
Idle
Read-out
Idle
Internal Registers
0
Filling up
Data
Available
Emptying
0
Filling up
Data
Available
Emptying
0
Figure 21 : Global timing diagram with separate SM-RO
Figure 22 shows a timing diagram wherein separate SM-RO cycles are mixed with combined SM-RO cycles.
After the Power-On-Reset phase, a SM measurement cycle is started. Once the DR pin is high, the data can
be read out. A SM command with extra clocks is used to combine the read-out and the start of the next
measurement cycle. With the extra clocks, the data of the internal registers is transferred to the MISO pin.
When the CS pin goes high, the next measurement cycle (SM) will be started.
Once the DR pin is high, a normal RO command is uploaded to bring the data to the MISO pin. If needed, the
settings in the user registers can be changed with the WR command and optionally the RR command can be
used to check if the right values were uploaded.
A new measurement cycle can be started with e.g. a normal SM command. When the DR pin is high, the
data can be transferred by uploading e.g. a SM command that combines the read-out and the start of a new
measurement cycle.
Figure 22: Global timing diagram with separate SM-RO and combined SM-RO together
REVISION 001 – JANUARY, 2013
39010xxxxx
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