Use one DMA channel with 2 different IPs ?

[Aahai.1]

Hello.

The project I am actually working on uses several peripherals such as USART ADC SPI etc.

I am trying to use as much DMA as I can, but there is something that I miss in the reference manual and on the internet.

Can I use ONE channel with TWO streams of TWO independant IPs ?

Can I use ONE channel with TWO streams of ONE IP ?

For instance with a STM32F427:

UART4 uses dma1 stream2 with channel4 and dma1 stream4 with channel 4

and

USART2 uses dma1 stream6 with channel4 and dma1 stream0 with channel 4

In this example :

Could I use the two streams for UART4 or only one stream at a time ?

Could I use every streams that I quoted for UART4 and USART2 (D1S2C4, D1S4C4, D1S6C4 and D1S0C4) at the same time ?

Thank you,

Have a nice day.

[TDK]

There is no restriction on using the same channel on multiple independent streams.

You can't use multiple channels within a single stream, and you can't have the same request mapped to multiple streams.

[waclawek.jan]

"Stream" in the DMA in 'F4 is one element of the DMA which performs the transfer.

"Channel" is only the setting of a stream's request multiplexer.

Read the DMA chapter in RM0090.

JW