STM8AL31E8X Datasheet, PDF (15/133 Pages) STMicroelectronics – Automotive 8-bit ultra-low-power MCU, 64 KB Flash, EEPROM, RTC, AES, LCD, timers, USARTs, I2C, SPIs, ADC, DAC, COMPs

STM8AL31E8x STM8AL3LE8x
Functional overview
BOR: Brownout reset
DMA: Direct memory access
DAC: Digital-to-analog converter
I²C: Inter-integrated circuit multimaster interface
IWDG: Independent watchdog
LCD: Liquid crystal display
POR/PDR: Power on reset / power-down reset
RTC: Real-time clock
SPI: Serial peripheral interface
SWIM: Single wire interface module
USART: Universal synchronous asynchronous receiver transmitter
WWDG: Window watchdog
3.1
Low-power modes
The high-density STM8AL3xE8x devices support five low-power modes to achieve the best
compromise between low-power consumption, short startup time and available wakeup
sources:
• Wait mode: CPU clock is stopped, but selected peripherals keep running. An internal
or external interrupt or a Reset is used to exit the microcontroller from Wait mode (WFE
or WFI mode).
• Low-power run mode: The CPU and the selected peripherals are running. Execution
is done from RAM with a low speed oscillator (LSI or LSE). Flash memory and data
EEPROM are stopped and the voltage regulator is configured in ultra-low-power mode.
The microcontroller enters Low-power run mode by software and exits from this mode
by software or by a reset.
All interrupts must be masked and are not used to exit the microcontroller from this
mode.
• Low-power wait mode: This mode is entered when executing a Wait for event in Low-
power run mode. It is similar to Low-power run mode except that the CPU clock is
stopped. The wakeup from this mode is triggered by a Reset or by an internal or
external event (peripheral event generated by the timers, serial interfaces, DMA
controller (DMA1), comparators and I/O ports). When the wakeup is triggered by an
event, the system goes back to Low-power run mode.
All interrupts must be masked and arenot used to exit the microcontroller from this
mode.
• Active-halt mode: CPU and peripheral clocks are stopped, except RTC. The wakeup
is triggered by RTC interrupts, external interrupts or reset.
• Halt mode: CPU and peripheral clocks are stopped, the device remains powered on.
The RAM content is preserved. The wakeup is triggered by an external interrupt or
reset. A few peripherals have also a wakeup from Halt capability. Switching off the
internal reference voltage reduces power consumption. Through software configuration
it is also possible to wake up the device without waiting for the internal reference
voltage wakeup time to have a fast wakeup time of 5 µs.
DocID027180 Rev 5
15/133
61