Introduction
To reduce code coupling and minimize firmware size, APP_DRV separates the DMA transmission mode of peripheral modules, which provides APIs for transmission in polling mode (app_xxx_transmit_sync), interrupt mode (app_xxx_transmit_async), and DMA mode (app_xxx_dma_transmit_async).
Taking the UART module as an example, the table below shows separation of DMA transmission for peripheral modules, with DMA mode setting, transmission, and control APIs added. Users can call these APIs for transmission in DMA mode.
| API | SoC Series | |||||
|---|---|---|---|---|---|---|
| GR551x | GR5526 | GR5x25 | GR533x | GR5405 | ||
| UART |
app_uart_init | Y | Y | Y | Y | Y |
| app_uart_deinit | Y | Y | Y | Y | Y | |
| app_uart_transmit_async | Y | Y | Y | Y | Y | |
| app_uart_transmit_sync | Y | Y | Y | Y | Y | |
| app_uart_receive_async | Y | Y | Y | Y | Y | |
| app_uart_receive_sync | Y | Y | Y | Y | Y | |
| app_uart_transmit_sem_sync | Y | Y | Y | Y | Y | |
| app_uart_receive_sem_sync | Y | Y | Y | Y | Y | |
| app_uart_flush | Y | Y | Y | Y | Y | |
| app_uart_abort | Y | Y | Y | Y | Y | |
| app_uart_abort_transmit | Y | Y | Y | Y | Y | |
| app_uart_abort_receive | Y | Y | Y | Y | Y | |
| app_uart_get_handle | Y | Y | Y | Y | Y | |
| app_uart_dma_init | Y | Y | Y | Y | Y | |
| app_uart_dma_deinit | Y | Y | Y | Y | Y | |
| app_uart_dma_transmit_async | Y | Y | Y | Y | Y | |
| app_uart_dma_receive_async | Y | Y | Y | Y | Y | |
| app_uart_transmit_dma_sg_llp | N | Y | Y | N | N | |
| app_uart_receive_dma_sg_llp | N | Y | Y | N | N | |
“Y” in Table 1 indicates that the corresponding item is supported, and “N” indicates not supported. The same applies to the following tables in this document.
Taking the UART module as an example, the figure below shows the DMA transmission process. Users need to call app_uart_dma_init to initialize DMA before calling app_uart_dma_transmit_async for data transmission in DMA mode.
