STM32W108CB datasheet(14/179 Pages) STMICROELECTRONICS

14 / 179 page

Description

STM32W108CB, STM32W108HB

14/179

Doc ID 16252 Rev 2

1.2.13

RTC (real-time clock) and backup registers

The RTC and the backup registers are supplied through a switch that takes power either on

VDD supply when present or through the VBAT pin. The backup registers are ten 16-bit

registers used to store 20 bytes of user application data when VDD power is not present.

The real-time clock provides a set of continuously running counters which can be used with

suitable software to provide a clock calendar function, and provides an alarm interrupt and a

periodic interrupt. It is clocked by a 32.768 kHz external crystal, resonator or oscillator, the

internal low power RC oscillator or the high-speed external clock divided by 128. The

internal low power RC has a typical frequency of 40 kHz. The RTC can be calibrated using

an external 512 Hz output to compensate for any natural crystal deviation. The RTC features

a 32-bit programmable counter for long term measurement using the Compare register to

generate an alarm. A 20-bit prescaler is used for the time base clock and is by default

configured to generate a time base of 1 second from a clock at 32.768 kHz.

1.2.14

Independent watchdog

The independent watchdog is based on a 12-bit downcounter and 8-bit prescaler. It is

clocked from an independent 40 kHz internal RC and as it operates independently from the

main clock, it can operate in Stop and Standby modes. It can be used as a watchdog to

reset the device when a problem occurs, or as a free running timer for application timeout

management. It is hardware or software configurable through the option bytes. The counter

can be frozen in debug mode.

1.2.15

Window watchdog

The window watchdog is based on a 7-bit downcounter that can be set as free running. It

can be used as a watchdog to reset the device when a problem occurs. It is clocked from the

main clock. It has an early warning interrupt capability and the counter can be frozen in

debug mode.

1.2.16

SysTick timer

This timer is dedicated for OS, but could also be used as a standard down counter. It

features:

●

A 24-bit down counter

●

Autoreload capability

●

Maskable system interrupt generation when the counter reaches 0.

●

Programmable clock source

●

General-purpose timers (TIMx)

There are three synchronizable general-purpose timers embedded in STM32W108 devices.

These timers are based on a 16-bit auto-reload up/down counter, a 16-bit prescaler and

feature 4 independent channels each for input capture, output compare, PWM or one pulse

mode output. This gives up to 161212 input captures / output compares / PWMs on the

largest packages.

The general-purpose timers can work together 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. They all have independent DMA request

generation.

STM32W108CB Scheda tecnica(PDF) 14 Page - STMicroelectronics

STM32W108CB Scheda tecnica(HTML) 14 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

Scheda tecnica Scarica

Link URL