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DSlob.1
Associate
September 21, 2020
Solved

How to solve the USART1 receive data via RXNE Interrupt problem on STM32F769NI-disco?

  • September 21, 2020
  • 3 replies
  • 1333 views

My STM32F769-disco is connected via built-in st-link 2.1 to my computer. I use the bypass USART for printf(). And that works OK for output data, whereas input data stuck before they come to USART->RDR and do up the RXNE flag indicating an interrupt.

Here the states of registers involved in the process.

USART1->CR1 = 0x0000002d (UE, RE, TE, RXNEIE)

USART1->ISR = 0x006200c2 (FE, TC, TXE, CMF, TEACK, REACK)

NVIC->ISER1->SETENA = 0x00000020

NVIC->IPR9->IPR_IN0 = 0xe0

So, it is seen that the USART is adjusted right. The hex-data of NVIC indicate the state of the interrupt had been set and it could be confirmed by changing the flag RXNEIE to TXEIE or TCIE (the interrupt starts to work as it has to, or, at least, as it is expected). 

PA9 and PA10 are set as push-pull alternatives AF7 at the highest speed.

I made a tryout to set RX as a floating input with no result. 

RCC is set correctly as well.

Is here a little secret maybe or something kind of?

Thanks any help. -)

This topic has been closed for replies.
Best answer by DSlob.1

My apologies. Soldering issue. Closed.

3 replies

Tesla DeLorean
Guru
September 21, 2020

Would need to clear​ the framing error to accept more data.

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DSlob.1
DSlob.1Author
Associate
September 21, 2020

Is it a SKU issue? I haven't any USART troubles with f0-f4 SKUs before. Do you know what a bit or a register I should kick?

DSlob.1
DSlob.1AuthorBest answer
Associate
September 22, 2020

My apologies. Soldering issue. Closed.