The maximum clock frequency of the STM32F102R8T6 is 24 MHz, but it can be overclocked to 36 MHz with a reduced voltage supply.
The clock settings can be configured using the Clock Control Register (RCC_CR) and the Flash Control Register (FLASH_CR). The RCC_CR register is used to select the clock source, while the FLASH_CR register is used to configure the flash memory access time.
The BOOT0 and BOOT1 pins are used to select the boot mode of the microcontroller. BOOT0 is used to select between the internal flash memory and an external memory, while BOOT1 is used to select the boot mode (flash memory or system memory).
The USART peripheral can be used for asynchronous communication. To use it, you need to configure the USART registers (USART_CR1, USART_CR2, and USART_BRR) to set the baud rate, word length, and stop bits. You also need to enable the USART clock and configure the GPIO pins as USART alternate function.
The NVIC is used to handle interrupts generated by peripherals. It allows you to prioritize interrupts and handle them efficiently. You need to configure the NVIC registers (NVIC_ISER, NVIC_ICER, NVIC_ISPR, and NVIC_ICPR) to enable and prioritize interrupts.