有人就这么干,不知道这些现成的函数是怎么来的
void usart_init(void)
{
/* Enable USART2 APB clock */
RCC_APB2PeriphClock_Enable(RCC_APB2PERIPH_USART1, ENABLE);
/* USART1 Pins configuration **************************************************/
{
/* Configure the GPIO ports */
GPIO_InitPara GPIO_InitStructure;
/* Connect pin to Periph */
GPIO_PinAFConfig(GPIOA , GPIO_PINSOURCE9, GPIO_AF_1);
GPIO_PinAFConfig(GPIOA , GPIO_PINSOURCE10, GPIO_AF_1);
/* Configure pins as AF pushpull */
GPIO_InitStructure.GPIO_Pin = GPIO_PIN_9 | GPIO_PIN_10;
GPIO_InitStructure.GPIO_Mode = GPIO_MODE_AF;
GPIO_InitStructure.GPIO_Speed = GPIO_SPEED_50MHZ;
GPIO_InitStructure.GPIO_OType = GPIO_OTYPE_PP;
GPIO_InitStructure.GPIO_PuPd = GPIO_PUPD_NOPULL;
GPIO_Init(GPIOA , &GPIO_InitStructure);
} //GPIO setting
{
USART_InitPara USART_InitStructure;
USART_DeInit(USART1);
USART_InitStructure.USART_BRR =9600;
USART_InitStructure.USART_WL = USART_WL_8B;
USART_InitStructure.USART_STBits = USART_STBITS_1;
USART_InitStructure.USART_Parity = USART_PARITY_RESET;
USART_InitStructure.USART_HardwareFlowControl = USART_HARDWAREFLOWCONTROL_NONE;
USART_InitStructure.USART_RxorTx = USART_RXORTX_RX | USART_RXORTX_TX;
USART_Init(USART1, &USART_InitStructure);
}
{
NVIC_InitPara NVIC_InitStructure;
/* Configure the NVIC Preemption Priority Bits */
/* Configure the preemption priority and subpriority:
- 1 bits for pre-emption priority: possible value are 0 or 1
- 3 bits for subpriority: possible value are 0..7
- Lower values gives higher priority
*/
/* Re-configure and enable USART interrupt to have the higher priority */
NVIC_InitStructure.NVIC_IRQ = USART1_IRQn;
NVIC_InitStructure.NVIC_IRQPreemptPriority = 5;
NVIC_InitStructure.NVIC_IRQSubPriority = 1;
NVIC_InitStructure.NVIC_IRQEnable = ENABLE;
NVIC_Init(&NVIC_InitStructure);
} //NVIC usart2 setting
/* Enable the USART1 Receive interrupt */
USART_INT_Set(USART1, USART_INT_RBNE, ENABLE);
/* USART enable */
USART_Enable(USART1, ENABLE);
}
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