2 years, 6 months ago.

Can F469NI run at 180mhz

I was hoping the F469NI would be running at 180mhz, but it's running at 168mhz. Is it possible to configure for 180mhz?

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The STM32F469 Discovery kit (32F469IDISCOVERY) allows users to easily develop applications with the STM32F469 high-performance MCUs with ARM®Cortex®-M4 core and Chrom-ART Accelerator™.
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2 Answers

2 years, 6 months ago.

Hello tom duningan,

I confirm the answer from Bill Bellis, We had to force the system clock at 168MHz to allow USB use.

Mbed code is already prepared in case you want to use 180MHz instead of 168 MHz. You can switch the values of the 2 defines in the file system_stm32f4xx.c

/* Select the SYSCLOCK  to start with (0=OFF, 1=ON) */
# define USE_SYSCLOCK_168 (1) /* Use external 8MHz xtal and sets SYSCLK to 168MHz */
# define USE_SYSCLOCK_180 (0) /* Use external 8MHz xtal and sets SYSCLK to 180MHz */

Kind regards

Thanks! I did not know that existed so I have been modifying the startup code myself!! :(

posted by Bill Bellis 24 Jan 2017
2 years, 6 months ago.

Yes. However due to the clock circuit inside of the 429 it can not support USB at 180MHz. If you download the STM Cube Mx application software from you can tweak the clock speed as desired and take the code it generates and merge it with mbed.