以上是我的相关程序，编译没有错误，不知哪里出了问题

void main(void) {   UART_Init(); //初始化UART      Send_Str("STM8S UART 实验！\r\n");//发送字符串   enableInterrupts(); //开启中断   while (1)   {       }    }

INTERRUPT_HANDLER(UART3_RX_IRQHandler, 21) {     /* In order to detect unexpected events during development,        it is recommended to set a breakpoint on the following instruction.     */    //UART3_ClearITPendingBit(UART3_IT_RXNE);    UART3_SendData8(UART3_ReceiveData8()); }

void UART_Init(void) {     UART3_DeInit();     UART3_Init((u32)9600, UART3_WORDLENGTH_8D, UART3_STOPBITS_1, UART3_PARITY_NO, UART3_MODE_TXRX_ENABLE);     UART3_ITConfig(UART3_IT_RXNE_OR, ENABLE);     UART3_Cmd(ENABLE);        enableInterrupts(); }

STM8S207R8T6,串口3不能实现接收中断，我用的是IAR库函数版本，麻烦各位大神帮我看看