下面的 IRQ 处理程序耗尽了传入的 32 字节数据的 USART3。第一个 IRQ TC 事件读取前 6 个字节，然后重新编程 DMA 引擎以读取最后 24 个字节。第二个 TC 对其重新编程以再次读取 header 此方法将允许使用 DMA 的可变长度消息。但是我似乎无法更改 DMA 起始地址。我希望能够将每条消息存储在一个单独的缓冲区中，但是它只是在收到每条消息时覆盖第一个缓冲区。我究竟做错了什么？微 Controller 是 STM32F103ze (Cortex-M3)。
void DMA1_Channel3_IRQHandler(void)
{
uint32_t tmpreg = 0;
/* Test on DMA1 Channel3 Transfer Complete interrupt */
if(DMA_GetITStatus(DMA1_IT_TC3))
{
if (rx3_dma_state == RECIEVE_HEADER )
{
DMA_Cmd(DMA1_Channel3, DISABLE);/* Disable DMA1_Channel2 transfer*/
// Now that have received the header. Configure the DMA engine to receive
// the data portion of the message
DMA_SetCurrDataCounter(DMA1_Channel3,26);
DMA_Cmd(DMA1_Channel3, ENABLE);
} else if ( rx3_dma_state == RECIEVE_MSG )
{
//CurrDataCounterEnd3 = DMA_GetCurrDataCounter(DMA1_Channel3);
DMA_Cmd(DMA1_Channel3, DISABLE);
/* Get Current Data Counter value after complete transfer */
USART3_Rx_DMA_Channel_Struct->CMAR = (uint32_t) RxBuffer3LookUp[rx_buffer_index];
DMA_SetCurrDataCounter(DMA1_Channel3, 6);
DMA_Cmd(DMA1_Channel3,ENABLE);
// Set up DMA to write into the next buffer slot (1 of 8)
++rx_buffer_index;
rx_buffer_index %= 8;
}
/* Clear DMA1 Channel6 Half Transfer, Transfer Complete and Global interrupt pending bits */
DMA_ClearITPendingBit(DMA1_IT_GL3);
}
// Update the state to read fake header of 6 bytes
// or to read the fake data section of the message 26 bytes
++rx3_dma_state;
rx3_dma_state %= 2;
isr_sem_send(dma_usart3_rx_sem);
}
最佳答案
你说:
...reprograms the DMA engine to read in the last 24 bytes.
但是你的代码说:
DMA_SetCurrDataCounter(DMA1_Channel3,26);
是吗？是 24 还是 26？
关于c - 使用 STM32F103 微 Controller (Cortex-M3) 重新编程 DMA 起始地址，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/7799891/