/* USART Enable TX pin active level inversion. 
TX pin signal values are inverted. (VDD =0/mark, Gnd=1/idle). */
void usart_enable_tx_inversion(uint32_t usart)
/* USART Enable TX pin active level inversion. 
TX pin signal values are inverted. (VDD =0/mark, Gnd=1/idle). */
void usart_enable_tx_inversion(uint32_t usart)
{
	USART_CR2(usart) |= USART_CR2_TXINV;
}