Features - Silicon Laboratories EFR32xG14 Wireless Gecko Reference Manual

28.2 Features

• Up to 16 sensors
• Autonomous sensor monitoring in EM0, EM1, and EM2
• Highly configurable decoding of sensor results
• Interrupt on sensor events
• Configurable enable signals to external sensors
• Circular buffer for storage of up to 16 sensor results
• Multiple evaluation modes minimize the need for software interaction
• Supports ADC0 sampling and evaluation
• Support for multiple sensor types
• LC sensors
• Capacitive sensing
• General analog sensors
28.3 Functional Description
The LESENSE module is capable of controlling on-chip peripherals in order to perform monitoring of different sensors with little or no
CPU intervention. LESENSE uses the analog comparators (ACMP) or ADC0 for measurement of sensor signals. LESENSE can also
control the VDAC to generate accurate reference voltages.
the LESENSE module.
The LESENSE module consists of a sequencer, an evaluation block, a decoder, and a RAM block:
• The sequencer handles interaction with other peripherals and controls timing of sensor measurements. It also includes a counter
that can be used to count pulses on the ACMP output.
• The evaluation block is used to process the data collected by the sequencer.
• To autonomously analyze sensor results, the LESENSE decoder provides the ability to define a finite state machine with up to 32
states, as well as define programmable actions upon state transitions. This allows the decoder to implement a wide range of decod-
ing schemes, such as quadrature decoding.
• A RAM block is used for storage of configuration and measurement results. This allows LESENSE to have a relatively large result
buffer enabling the chip to remain in a low energy mode for long periods of time while collecting sensor data.
POSSEL
GND
VADIV
VBDIV
VLP
VDAC0 Internal
Connections
Dedicated BUS0
BUS1
BUS2
APORT
BUS3 +
BUS4
GND
-
VADIV
VBDIV
VLP
VDAC0 Internal
Connections
Dedicated BUS0
BUS1
BUS2
APORT
BUS3
BUS4
NEGSEL
VDAC0_OUT0
VDAC0_OUT1
LES_CHn
LES_ALTEXn
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ACMP0
ACMP1
Register bitfields
overridden by LESENSE
EN
CSRESSEL
CSRESEN
PERCTRL_ACMP0INV
PERCTRL_ACMP1INV
BIASPROG FULLBIAS
HYST1 HYST0
DIVVA1 DIVVA0
DIVVB1 DIVVB0
CH0
CHnDATA
CHnCTRL_EN
CH1
VDAC0
OPAnOUT_PEN
Figure 28.1. LESENSE Block Diagram
LESENSE - Low Energy Sensor Interface
Figure 28.1 LESENSE Block Diagram on page 932
ACMP sample register
CURCH[3]
Saturating counter
ADC sample register
CH_INTERACT_SAMPLE
SCANMASK
ADC0
Reference Manual
shows an overview of
CH_INTERACT_SAMPLE
SCANRES
Sliding window
SENSORSTATE
Step Detect
PRS input
Threshold compare
CH_EVAL_MODE
Rev. 1.1 | 932
LESENSE
LESENSE
DECODER