STM32 UART DMA RX/TX

[Tilen MAJERLE]

STM32 UART DMA RX/TX

This is an application note and contains a list of examples about 2 distinct topics:

 

• Receiving data with UART and DMA when application does not know in advance size of bytes to be received
• Transmitting data with UART and DMA to avoid CPU stalling and use CPU for other purposes

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[CWang.16]

Have STPM32H7 CPU running in 108 Mhz, and UART1 pull off PLL3 @50 Mhz, set baud rate at 3375000 with 8x oversampling rate.

Do see the Tx signal by DMA (303 ns each baud ) out to device and replied with about 302 ns baud, signal is clean on the scope, however, the DMA Rx never catch anything. Both are working fine when it is half the baud rate( 1687500 with 16x oversampling ).

What else need to change for DMA Rx?