Datasheet

Functional overview STM32F303x6/x8
14/121 DocID025083 Rev 7
3.2.3 Boot modes
At startup, BOOT0 pin and BOOT1 option bit are used to select one of the three boot
options:
• Boot from user Flash memory
• Boot from system memory
• Boot from embedded SRAM
The boot loader is located in system memory. It is used to reprogram the Flash memory by
using USART1 (PA9/PA10), USART2 (PA2/PA3), I2C1 (PB6/PB7).
3.3 Cyclic redundancy check calculation unit (CRC)
The CRC (cyclic redundancy check) calculation unit is used to get a CRC code using a
configurable generator polynomial value and size.
Among other applications, CRC-based techniques are used to verify data transmission or
storage integrity. In the scope of the EN/IEC 60335-1 standard, they offer a means of
verifying the Flash memory integrity. The CRC calculation unit helps to compute a signature
of the software during runtime, to be compared with a reference signature generated at link-
time and stored at a given memory location.
3.4 Power management
3.4.1 Power supply schemes
• V
SS
, V
DD
=
2.0 to 3.6 V: external power supply for I/Os and the internal regulator. It is
provided externally through V
DD
pins.
• V
SSA
, V
DDA
= 2.0 to 3.6 V: external analog power supply for ADC, DACs, comparators
operational amplifiers, reset blocks, RCs and PLL.The minimum voltage to be applied
to V
DDA
differs from one analog peripherals to another. See Table 3 below,
summarizing the V
DDA
ranges for analog peripherals. The V
DDA
voltage level must be
always greater or equal to the V
DD
voltage level and must be provided first.
• V
DD18
= 1.65 to 1.95 V (V
DD18
domain): power supply for digital core, SRAM and Flash
memory. V
DD18
is internally generated through an internal voltage regulator.
• V
BAT
= 1.65 to 3.6 V: power supply for RTC, external clock 32 kHz oscillator and
backup registers (through power switch) when V
DD
is not present.
Table 3. V
DDA
ranges for analog peripherals
Analog peripheral Min. V
DDA
supply Max. V
DDA
supply
ADC/COMP 2 V 3.6 V
DAC/OPAMP 2.4 V 3.6 V
Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.