RTL8722DM(AMB21) UART3 not working

I started development with Standard SDK(which is downloaded GitHub) on AMB21 evaluation board.
I referenced the uart_stream_data example(example_sources\UART\mbed\uart_stream_dma) and add in the main.c and it works.
Then I tried to use UART0 and UART3 with PA25 and PA26(which are defined in the serial_api.c), but it didn’t work. What might be the reason?
By the way, which repository is the most recommaneded? The newest repository or the QC-V1.0.0 or Realteck website?

Hi @Po_Quan_Hsieh

UART 3 does not have a DMA interface, thus the uart_stream_dma example will not work with this UART. If you wish to use UART 3, you should use the non-DMA examples.

It is recommended that you use the Release V1.0.0 version.

Hi @wyy ,
Thanks for your help, after applying uart_stream_irq example into the main.c, the UART0 DMA and UART3 IRQ both work fine.