USART_CR1_OVER8
cr1 |= USART_CR1_OVER8;
stm32_usart_set_bits(port, ofs->cr1, USART_CR1_OVER8);
cr1 &= ~USART_CR1_OVER8;
stm32_usart_clr_bits(port, ofs->cr1, USART_CR1_OVER8);
over8 = *cr1 & USART_CR1_OVER8;
over8 = cr1 & USART_CR1_OVER8;