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STM32L151xC/C-A STM32L152xC/C-A
Functional overview
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3.16.2
Basic timers (TIM6 and TIM7)
These timers are mainly used for DAC trigger generation. They can also be used as generic
16-bit time bases.
3.16.3 SysTick
timer
This timer is dedicated to the OS, but could also be used as a standard downcounter. It is
based on a 24-bit downcounter with autoreload capability and a programmable clock
source. It features a maskable system interrupt generation when the counter reaches 0.
3.16.4 Independent
watchdog
(IWDG)
The independent watchdog is based on a 12-bit downcounter and 8-bit prescaler. It is
clocked from an independent 37 kHz internal RC and, as it operates independently of the
main clock, it can operate in Stop and Standby modes. It can be used either 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.
3.16.5 Window
watchdog
(WWDG)
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.
3.17 Communication
interfaces
3.17.1 I²C
bus
Up to two I²C bus interfaces can operate in multimaster and slave modes. They can support
standard and fast modes.
They support dual slave addressing (7-bit only) and both 7- and 10-bit addressing in master
mode. A hardware CRC generation/verification is embedded.
They can be served by DMA and they support SM Bus 2.0/PM Bus.
3.17.2 Universal
synchronous/asynchronous receiver transmitter (USART)
The three USART interfaces are able to communicate at speeds of up to 4 Mbit/s. They
support IrDA SIR ENDEC and have LIN Master/Slave capability. The three USARTs provide
hardware management of the CTS and RTS signals and are ISO 7816 compliant.
All USART interfaces can be served by the DMA controller.
3.17.3
Serial peripheral interface (SPI)
Up to three SPIs are able to communicate at up to 16 Mbits/s in slave and master modes in
full-duplex and half-duplex communication modes. The 3-bit prescaler gives 8 master mode
frequencies and the frame is configurable to 8 bits or 16 bits. The hardware CRC
generation/verification supports basic SD Card/MMC modes.