EVB90129 Datasheet, PDF (10/13 Pages) Melexis Microelectronic Systems – Asset management and monitoring (security and integrity)

EVB90129
MLX90129 Evaluation Board
5 Miscellaneous peripheries
5.1 Padlock or security device function
The pin 7 of the MLX90129 can be used as a Padlock
function, else it has to be connected to the ground. The
padlock function allows generating an IRQ when the
jumper between pin 7 and the ground is removed.
The schematic shows the Padlock jumper implementation
and the following register configuration allows configuring
the MLX90129 in order to use this feature.
TP3
Black
CON13
2
1
Pad Lock
GND
7 _NC
Content
Power configuration
# Hexa 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
12 0A00 0 0 0 0 1 0 1 0 0 0 0 0 0 0 0 0
5.2 External SPI memory
The MLX90129 can be connected to a SPI external
memory in order to store a large amount of data during a
data logging application. An external 128Kbit memory is
available on the EVB90129. It can be connected by
setting the jumper CON3 / ExtMemSelector. In this
configuration, the external memory is supplied by the
regulated voltage output (VREG) of the MLX90129. The
SPI pins (SS / SCK / MISO /MOSI) are connected to the
MLX90129 SPI pins. The CON4 / SS_selector allows
connecting the SS pin of the MLX90129 to the SS pin of
the external memory. The schematic shows the memory
implementation and the following register configuration
allows the MLX90129 to communicate with the memory
as a SPI master. More information is available in the
MLX90129 datasheet.
The SPI memory datasheet gives the following
commands:
- Write Enable = 0x06
- Write Memory = 0x02
- Read Memory = 0x03
CON3
2
1
VREG
Ext MemSelector
R4
100K
MOSI 5
SCK 6
7
3
SS_MEM 1
DQ
C
HOLD
W
S
C7
Close to pin Vcc
100n
GND
2 MISO
U2
CAT25128
GND
The MLX90129 has to be in SPI master mode. The bit 0 of the Device security register has to be set either in
EEPROM (restricted access by RFID) or in the register files.
Content
Control word
Command codes
Device security
# Hexa 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
0D 0639 0 0 0 0 0 1 1 0 0 0 1 1 1 0 0 1
0E 0203 0 0 0 0 0 0 1 0 0 0 0 0 0 0 1 1
05 3FF1 0 0 1 1 1 1 1 1 1 1 1 1 0 0 0 1
5.3 External XTAL
For Auto logging function an external precise clock can
be used to enhance timing between two sensor
acquisitions. The 32,768 KHz crystal is connected
between the pins XIN and XOUT of the MLX90129. The
bit 14 of the Internal Devices Domain, address #03 has to
be set.
Y1
XIN 1 4
XOUT
32K768
390129012901
Rev 003
Page 10 of 13
Evaluation Board
June-2010