Hi,
I've configured a USART TX DMA channel (using the graphical config tool) that I trigger from software when bytes are available to be transmitted using:
DMA_DoChannelSoftwareTrigger(DMA0_DMA_BASEADDR, DMA0_LOG_UART_DMA_CHANNEL);
This works fine, but only with a fixed number of bytes each trigger.
How can I update the DMA channel so it knows how many bytes it should transfer?
Thanks in advance.
Kind regards,
Remco Poelstra
Solved! Go to Solution.
Hello Remco Poelstra,
Yes, the DMA only can transfer fixed number of bits.
And a ring buffer DMA maybe suit for you , there is demo"lpcxpresso845max_usart_transfer_rb_dma" under SDK, you can have a look.
Regards,
Alice
Thanks for the reply.
I'll look into the ring buffer example. It might indeed be what I need.
Kind regards,
Remco Poelstra
Hello Remco Poelstra,
Yes, the DMA only can transfer fixed number of bits.
And a ring buffer DMA maybe suit for you , there is demo"lpcxpresso845max_usart_transfer_rb_dma" under SDK, you can have a look.
Regards,
Alice
Hi,
I'm using LPC844.
Kind regards,
Remco Poelstra
Hi
Please let us know your chip part number, thus we can assign right engineer for your issue.
Thanks,
Jun Zhang