ST STM32G0 1 Series Reference Manual page 67

Note: If the device is programmed for a first time but the Option bytes are not reloaded, the device
still selects System memory as a boot area after a System reset.
Physical remap
Once the boot mode is selected, the application software can modify the memory accessible
in the code area. This modification is performed by programming the MEM_MODE bits in
the SYSCFG configuration register 1
Embedded boot loader
The embedded boot loader is located in the System memory, programmed by ST during
production. It is used to reprogram the Flash memory using one of the following serial
interfaces:
•
USART1, USART2, I2C1 and I2C2 (applies to all devices)
•
USART3, SPI1, and SPI2 (applies to STM32G071xx and STM32G081xx and to
STM32G0B1xx and STM32G0C1xx)
•
USB (DFU) and FDCAN2 (applies to STM32G0B1xx and STM32G0C1xx)
For further details, refer to the device data sheets and AN2606.
68/1391
(SYSCFG_CFGR1).
RM0444 Rev 5
RM0444