Datasheet
DocID17943 Rev 6 21/134
STM8L15xx8, STM8L15xR6 Functional overview
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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, DAC1 and the internal reference voltage V
REFINT
. It also
provides a set of registers for efficiently managing the charge transfer acquisition sequence
(see Section 3.13: Touch sensing).
3.13 Touch sensing
The high density and medium+ density STM8L15xx 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 (glass, plastic, ...). The capacitive variation introduced by the 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 the high density and medium+
density STM8L15xx devices, the acquisition sequence is managed by software and it
involves analog I/O groups and the routing interface.
Reliable touch sensing solution can be quickly and easily implemented using the free STM8
touch sensing firmware library.
3.14 Timers
The high density and medium+ density STM8L15xx devices contain one advanced control
timer (TIM1), three 16-bit general purpose timers (TIM2,TIM3 and TIM5) and one 8-bit basic
timer (TIM4).
All the timers can be served by DMA1.
Table 3 compares the features of the advanced control, general-purpose and basic timers.
Table 3. Timer feature comparison
Timer
Counter
resolution
Counter
type
Prescaler factor
DMA1
request
generation
Capture/compare
channels
Complementary
outputs
TIM1
16-bit up/down
Any integer
from 1 to 65536
Yes
3 + 1 3
TIM2
Any power of 2
from 1 to 128
2
None
TIM3
TIM5
TIM4 8-bit up
Any power of 2
from 1 to 32768
0