我正在为STM32F处理器上的UART开发一个双缓冲区。下面的示例在UART ISR每次运行时将数据添加到缓冲区。当主进程想要从中提取数据时,这个缓冲区就会被交换。
我担心可能的拐角情况。在交换缓冲区之后,在重置接收缓冲区计数之前,ISR可能会触发。这意味着我的缓冲区大小和计数将不同步。
处理这个角落的案子最好的方法是什么?
uint8_t rxBufferA[MAX_RX_BUFFER_SIZE];
uint8_t rxBufferB[MAX_RX_BUFFER_SIZE];
uint8_t *receivingBuffer;
uint8_t *processingBuffer;
volatile uint32_t rxBufferSize;
uart_isr() {
receivingBuffer[rxBufferSize++] = RECEIVE_DATA_REGISTER
}
main() {
receivingBuffer = &rxBufferA;
processingBuffer = &rxBufferB;
while(1) {
if (rxBufferSize > 0) {
uint32_t i = 0;
uint8_t *ptemp = receivingBuffer;
uint8_t bufferSize = 0;
/* zero out processing buffer */
memset(processingBuffer, 0, MAX_RX_BUFFER_SIZE);
/* swap receiving and processing buffers */
receivingBuffer = processingBuffer
processingBuffer = ptemp;
/* WHAT IF THE ISR FIRES HERE??? */
/* save off buffer size and reset count */
bufferSize = rxBufferSize;
rxBufferSize = 0;
/* process rx data */
}
}
}
最佳答案
你需要关键部分。交换缓冲区时禁用用户中断。
BTW不需要调零
关于c - 在双缓冲区交换期间处理UART ISR,我们在Stack Overflow上找到一个类似的问题:https://stackoverflow.com/questions/56137758/