DVK90129 Melexis Inc, DVK90129 Datasheet - Page 35

• Manufacturer Part Number: DVK90129
• Description: DEVELOPMENT KIT MLX90129
• Manufacturer: Melexis Inc
• Series: -r
• Type: Development kitr

Specifications of DVK90129

• Contents: Board, Proxima RF™ Desktop Reader
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant
• For Use With/related Products: MLX90129

Interrupt of DMA process
The microcontroller or the RFID base-station can read the DMA status register and access the DMA
configuration register to start and control the DMA processing. At any time, they can hold the DMA process
and check the current status of the copied data (telling how many words have been copied). Then, they can
change the DMA configuration to a new one or continue the processing. While the DMA is processing data or
is on hold, any change of the parameters in the DMA configuration words does not cause the expected
changes in the behaviour.
End of DMA process
At the end of the sequence, the MLX90129 may enter its sleep mode or its stand-by mode. During the Sleep
mode, the system may be interrupted by a RFID field, or by the SS line asserted low during 1.5ms.
9.1.3 Setup of the Automatic Logging Mode
Setup
In order to enable the automatic logging mode, the following sequence must be run:
_ Setup the DMA configuration word
_ Setup the DMA source start address, DMA destination start address and the DMA length.
_ If an external EEPROM is used, setup the SPI-master configuration and command word
_ setup the sensor interface configurations in the EEPROM.
_ Setup the Sensor control word and the Sensor thresholds words (if required)
_ Setup the Wake-up Timer configuration word
_ Setup the logging period in the wake-up timer
_ To enable the DMA operation, the bit Processing Control of the DMA configuration register must be reset.
_ Set the bit Automatic Logging enable in the wake-up timer configuration to ’1’.
All these actions can be performed automatically after the system boot: the required configuration can be set
in the EEPROM. Then, after power-on, the system reads this configuration and performs the programmed
actions. It is not mandatory to store all the data from a sensor at each iteration, but only the data fitting the
conditions defined in the bits Data logging control of the register word called Sensor[x] Control word.
Logging several sensors and time-stamp
When more than one sensor is selected as a source of automatic logging, the DMA stores subsequently all
the sensor output data in the selected memory. The stored data has a prefix to identify them:
Bit
Definition
The prefix code is defined in the following table:
Prefix code
00
01
10
11
3901090129
Rev 007
Related sensor or parameter
Sensor 0
Sensor 1
Sensor 2
Iteration index (Time stamp)
Prefix
15:14
13.56MHZ SENSOR TAG / DATALOGGER IC
Page 35 of 56
ADC output code
13:0
MLX90129
Data Sheet
March 2011