Can you support 216MHz when using STM32F746 1.8V?

[sim20]

Hi all,

​

I am using STM32F746

I want to check if it can be used at 216MHz when using at 1.8V.

There is some confusion on the data sheet that makes it difficult to determine. (Attachments)

Please help me ~

Thank you,

Best regards.​

Gyosun.

[Imen.D]

Hello,

STM32F7 MCUs offer three voltage scales:

• Scale 1: up to 180 MHz in normal mode and up to 216 MHz in over-drive mode.
• Scale 2: up to 168 MHz and 180 MHz is possible with Over-drive.
• Scale 3: up to 144 MHz

By passing the voltage regulator, power can be saved at both 3.3V and 1.8V.

I recommend you to refer to this AN4749 Application note Managing low-power consumption on STM32F7 Series microcontrollers.

https://www.st.com/content/ccc/resource/training/technical/product_training/group0/c0/b9/97/5d/44/62/49/3d/STM32F7_System_PWR/files/STM32F7_System_PWR.pdf/jcr:content/translations/en.STM32F7_System_PWR.pdf

Best Regards,

Imen

[Piranha]

And again ST's employee is not even able to understand what the question is about. It's about VDD not core voltage!

[Piranha]

> I want to check if it can be used at 216MHz when using at 1.8V.

Table 18 suggests that the maximum is 180 MHz and overdrive must be off, which sounds sane. ST should know better, if their support will understand the question...

[sim20]

Yes, as Piranha said, I asked if it was possible to use 216MHz when the VDD voltage was 1.8V.

Can you give me a clear answer on this?

Thank you, 

Best regards.​ 

Gyosun.

[Imen.D]

Hello @sim20​ ,

You will find more clarification in the following tables :

• reference manual: Table "Number of wait states according to CPU clock (HCLK) frequency":

• Datasheet: "Table 18. General operating conditions", note that the over-drive mode is not supported at the voltage ranges from 1.7 to 2.1 V.

I hope that is clear now for you.

Best Regards

Imen

[sim20]

hello Imen,

​

As a result, when VDD is 1.8V, it can only be used up to 180MHz.

Thank you for answer.​

Best regards.​ 

Gyosun.