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NSemrHomeInit
Associate III
October 7, 2020
Solved

Clock speed stm32f429i example package

  • October 7, 2020
  • 2 replies
  • 947 views

Dear ST Hello,

could you tell me please the real clock value set in this example,

\STM32Cube\Repository\STM32Cube_FW_F4_V1.25.1\Projects\STM32F429I-Discovery\Examples\SPI\SPI_FullDuplex_ComDMA

The clock frequency between master and slave must be equal, does the frequency communication is imposed by the master since they have to be the same?

Thank you in advance,

S.Tarik,

This topic has been closed for replies.
Best answer by Imen.D

It depends on the DSP used.

You can configure the baude rate of CR register (calculate APB1/baud rate configured, APB2/baud rate).

In fact, the prescaler define the SPI BUS clock.

0693W000004J9XhQAK.png

2 replies

Technical Moderator
October 7, 2020

Hello @NSemrHomeInit​ ,

The clock is imposed by the master.

What do you mean by real clock w the baudrate is configured in SPIx_CR1 register ?

Imen

"When your question is answered, please close this topic by clicking ""Accept as Solution"".ThanksImen"
NSemrHomeInit
Associate III
October 8, 2020

Hello Imen,

I am trying an SPI communication between the two boards, DSP and STM32F.

Do i have to configure the clock of the DSP the same as the SMT32F?

I have two microcontroller, both are clock configured, but in the end, the master clock will be considered as a clock for the spi bus.

Tesla DeLorean
Guru
October 8, 2020

The master supplies the only clock and the transmit/receive is symmetrical, but can occur on different clock edges.​

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NSemrHomeInit
Associate III
October 8, 2020

Thank you clive1 :)