STM32F103: Using DMA1 Channel 3 for SPI1_TX and USART3_RX same time

[cfrpg]

I'm currently working on a project using an STM32F103RET microcontroller. I need to use SPI1 to write log data to a flash chip at an rate of 64 bytes every 20 milliseconds, and use USART3 monitoring external communication, receiving an average of 30 bytes every 10 milliseconds. To minimizing CPU usage, I'm trying use DMA to handle data transmission, and find that SPI1_TX and USART3_RX share a same DMA channel (DMA1,channel 3).

The question is, is it possible to use DMA1 Channel 3 for both SPI1_TX and USART3_RX simultaneously on an STM32F103?

(My code runing in main loop without RTOS)

[waclawek.jan]

No.

JW

[SofLit · Accepted solution]

Hello,

Unfortunately it’s not possible. Need to select another USART or SPI instance.