2023-12-18 11:44 PM
I try to set DMA setting of USART1_RX, USART2_TX both. Bit MX Error message is occurred. as below figure.
Solved! Go to Solution.
2023-12-19 06:25 AM
The chip has a limited amount of DMA streams. If all the streams possible for USART1 are being used for something else, you will be unable to add one for the USART1.
2023-12-19 12:33 AM
Hello @Da2 and welcome to the ST Community
I can't reproduce your issue. can you share your .ioc file so we can test it?
Best Regards.
STTwo-32
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2023-12-19 06:25 AM
The chip has a limited amount of DMA streams. If all the streams possible for USART1 are being used for something else, you will be unable to add one for the USART1.
2023-12-19 03:29 PM
2023-12-19 03:38 PM
Let me know how to set DMA Streams.
2023-12-19 03:52 PM - edited 2023-12-19 03:53 PM
You can hover over the red area to find out the reason it can't be set. In this case, because it conflicts with UART8_RX.
Okay, now we know why it can't be enabled. But why does it conflict? Take a look in the reference manual at the DMA request mapping table and look at the entries for USART2_TX and UART8_RX. The only option is DMA1 stream 6, which can only be dedicated to one at a time.
Therefore, you cannot use DMA with USART2_TX and UART8_RX at the same time.
Your options are to use a different chip (outside the STM32F4 family), or use a different peripheral, or don't use DMA with one of them.
(Note that your post says USART1_RX, USART2_TX, but your IOC only has UART8_RX enabled. If you don't need UART8_RX just disable it and use USART2_TX instead.)
2023-12-19 06:07 PM
Thank you. Let me know the manual of Table 42. DMA1 request mapping.
2023-12-19 06:14 PM
I got manula from your home page. Thank you a lot.