STM8L151X4 Datasheet, PDF (21/142 Pages) STMicroelectronics – Advanced STM8 core

STM8L151x4/6, STM8L152x4/6
Note:
ADC1 can be served by DMA1.
Functional overview
3.10
Note:
Digital-to-analog converter (DAC)
• 12-bit DAC with output buffer
• Synchronized update capability using TIM4
• DMA capability
• External triggers for conversion
• Input reference voltage V_REF+ for better resolution
DAC can be served by DMA1.
3.11
Ultra-low-power comparators
The medium-density STM8L151x4/6 and STM8L152x4/6 embed two comparators (COMP1
and COMP2) sharing the same current bias and voltage reference. The voltage reference
can be internal or external (coming from an I/O).
• One comparator with fixed threshold (COMP1).
• One comparator rail to rail with fast or slow mode (COMP2). The threshold can be one
of the following:
– DAC output
– External I/O
– Internal reference voltage or internal reference voltage sub multiple (1/4, 1/2, 3/4)
The two comparators can be used together to offer a window function. They can wake up
from Halt mode.
3.12
System configuration controller and routing interface
The system configuration controller provides the capability to remap some alternate
functions on different I/O ports. TIM4 and ADC1 DMA channels can also be remapped.
The highly flexible routing interface allows application software to control the routing of
different I/Os to the TIM1 timer input captures. It also controls the routing of internal analog
signals to ADC1, COMP1, COMP2, DAC and the internal reference voltage V_REFINT. It also
provides a set of registers for efficiently managing the charge transfer acquisition sequence
(Section 3.13: Touch sensing).
3.13
Touch sensing
Medium-density STM8L151x4/6 and STM8L152x4/6 devices provide a simple solution for
adding capacitive sensing functionality to any application. Capacitive sensing technology is
able to detect finger presence near an electrode which is protected from direct touch by a
dielectric (example, glass, plastic). The capacitive variation introduced by a finger (or any
conductive object) is measured using a proven implementation based on a surface charge
transfer acquisition principle. It consists of charging the electrode capacitance and then
transferring a part of the accumulated charges into a sampling capacitor until the voltage
across this capacitor has reached a specific threshold. In medium-density STM8L151x4/6
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