Important facts about the stm32 in general and for programming it

• Multiple external pins can be associated to interrupts
• Clock must be initialized by software. The stm32 is able to detect a failure of the external clock and fall-back on the internal clock and issue an interrupt. Connect this to a red led! Blink a special pattern to indicate this condition. Use time measurement that adjust to the different cpu clocks by reading from the clock source register?

• Booting pins working not clear
• Reset circuitry not necessary, is already included. It can generate interrupts if voltage goes down. The voltage threshold must be configured. Check PVD.
• Standby mode. SRAM and register information gets lost.
• DMA supports circular buffers automatically
• TIM1 (advance timer) can do 0-100% PWM 4+3complementary
• TIMx (3 normal timers) 4 PWMs
• Timer Link allows synchronization between timers.
• Watchdog can operate as a normal independent timer.
• SysTick timer can operate as a normal timer.
• Two Spis operate up to 18Mbits/s
• GPIOs can do output push-pull and open-drain, input can do pull-up-down,tristate. Analog inputs are not high current, the rest are. 18MHz toggling speed.
• Two ADC. 16 channels. Automatic conversion over a group of channels. Watchdog threshold, can generate an interrupt. ADC conversion triggering can be connected to timers and DMA. Termometer connected to ADC12_in16.
• There must be multiple rail capacitors. Take a look on Figure 12. stm32 medium density pdf.
• Each I/O pin hold 25mA ABS max, 8mA nom and sink 20mA nom output current.
• For enable prefetching, clock setting and bus prescaling must be previously configured
• Disabling peripherals is good for current consumption.
• Flash uses two wait states. Maybe running code from SRAM could be good.
• Reducing CPU operating frequency reduces current consumption proportionally
• Sleep mode helps significantly when peripherals are disabled.
• Stop and Standby mode are in the uA order.
• ADC freq 0.6-14MHz clock, sampling: 0.05-1MHz. Conversion speed is limited by the input capacitance, it distorts the signal in a non-correctable way. Fig32,33. stm32_medium_density pdf. Temperature sensor information table 49 stm32_medium pdf.