STM32L151VD datasheet(28/140 Pages) STMICROELECTRONICS

28 / 140 page

Functional overview

STM32L151xD STM32L152xD

28/140

Doc ID 022027 Rev 6

Capacitive sensing technology is able to detect the presence of a finger near a sensor 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 sensor 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. The capacitive sensing acquisition only requires few external components to

operate.

Reliable touch sensing functionality can be quickly and easily implemented using the free

STM32L1xx STMTouch touch sensing firmware library.

3.17

Timers and watchdogs

The ultra-low-power STM32L15xxD devices include seven general-purpose timers, two

basic timers, and two watchdog timers.

Table 8 compares the features of the general-purpose and basic timers.

3.17.1

General-purpose timers (TIM2, TIM3, TIM4, TIM5, TIM9, TIM10 and

TIM11)

There are seven synchronizable general-purpose timers embedded in the STM32L15xxD

devices (see Table 8 for differences).

TIM2, TIM3, TIM4, TIM5

TIM2, TIM3, TIM4 are based on 16-bit auto-reload up/down counter. TIM5 is based on a 32-

bit auto-reload up/down counter. They include a 16-bit prescaler. They feature four

independent channels each for input capture/output compare, PWM or one-pulse mode

output. This gives up to 16 input captures/output compares/PWMs on the largest packages.

TIM2, TIM3, TIM4, TIM5 general-purpose timers can work together or with the TIM10,

TIM11 and TIM9 general-purpose timers via the Timer Link feature for synchronization or

event chaining. Their counter can be frozen in debug mode. Any of the general-purpose

timers can be used to generate PWM outputs.

Table 8.

Timer feature comparison

Timer

Counter

resolution

Counter type

Prescaler factor

DMA request

generation

Capture/compare

channels

Complementary

outputs

TIM2,

TIM3,

TIM4

16-bit

Up, down,

up/down

Any integer between

1 and 65536

Yes

TIM5

32-bit

Up, down,

up/down

Any integer between

1 and 65536

Yes

TIM9

16-bit

Up, down,

up/down

Any integer between

1 and 65536

TIM10,

TIM11

16-bit

Any integer between

1 and 65536

TIM6,

TIM7

16-bit

Any integer between

1 and 65536

Yes

STM32L151VD Arkusz danych(PDF) 28 Page - STMicroelectronics

STM32L151VD Arkusz danych(HTML) 28 Page - STMicroelectronics

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 ...More

Arkusz danych Pobierz

Link URL