STM32CubeMX setting for STM32F7 SPI

[DarkTaipei]

Posted on September 17, 2016 at 00:56

Hi,

I used to work on STM32F4 and now are evaluating STM32F7. When I tried to create a project with STM32F769NI with SPI. I found that I can't set the Prescaler to 2 (APB2 = 108Mhz) which will result the SPI6 to 54Mhz.

The error message is ''With this Prescaler value and APB2 Clock Frequency (108.0 MHz), Baud Rate is more than : 50.0 MBit/s. 

But the datasheet clear said it can go up to 54MHz. So..

The program is wrong, datasheet is wrong or I am wrong? (SPI 6, master mode with full duplex). I also set the voltage to 3.3. 

Regards,

TYY

#stm32f7-spi

[slimen]

Posted on September 19, 2016 at 15:49

Hi,

Could you precise which version of CubeMx are you using ?

Regards

[Nesrine M_O]

Posted on September 19, 2016 at 15:52

Hi TONYY,

Could you please precise which CubeMX version are you using?If you are using an old version, I recommend you to use the latest: 4.16.1

-Syrine-

[DarkTaipei]

Posted on September 19, 2016 at 17:17

I believe I am at 4.1, I updated it a few days ago.

Tony

________________

Attachments :

mx1.jpg : https://st--c.eu10.content.force.com/sfc/dist/version/download/?oid=00Db0000000YtG6&ids=0680X000006Htpy&d=%2Fa%2F0X0000000aXY%2FiGZs30_ue3xJUrRsLR3eCwkyvW8opMaKfxX5cwy2ljk&asPdf=false

mx2.jpg : https://st--c.eu10.content.force.com/sfc/dist/version/download/?oid=00Db0000000YtG6&ids=0680X000006HtmW&d=%2Fa%2F0X0000000aWq%2FwcU8mog91BamfjasxxtdL03tdn19U1rgbetxY9rbSa8&asPdf=false

[Nesrine M_O]

Posted on September 20, 2016 at 10:45

Hi TONYY,

Thank you for your feedback. The issue has been reported internally.

-Syrine-

[stm32cube-t]

Posted on January 02, 2017 at 16:15

Original issue has been fixed in 4.18 release: 'With SPI on STM32F769NI, set the Prescaler to 2 (APB2 = 108Mhz), set the voltage range to 3.3 V. With this Prescaler value and APB2 Clock Frequency (108.0 MHz), maximum Baud Rate is 50.0 MBit/s when we should be able to reach SPI6 at 54Mhz'.

Indeed:

 - The max value depends on voltage range. So 54MHz, should be proposed if application is running 3.3V typical.

- At low voltage range, the delay on the pad is longer and limits the max frequency.