Fast pin toggling on STMH723

[Mazz]

I have been trying to see how fast can I toggle the pins on STM32H7 MCU. I'm using a nucleo-H723zg board. 

the clock configs are at the highest (550Mhz for CPU, 275 for APB and AHB), the pins are configured as very high speed. 
But still with a simple while loop such as 

while (1) {

GPIOE->BSRR = (uint32_t) GPIO_PIN_2;

GPIOE->BSRR = (uint32_t) GPIO_PIN_2 << 16U;

}

the frequency of the PWM I see on the oscilloscope is 7.3 MHz max. Ofcourse the PWM is not the final goal
but I wanted to see how fast this mcu can implemnet the bit toggling.
Am I doing something wrong here?

[SofLit]

Hello, 

I do agree with what others said regarding the architecture and H7 family is not intended to do that kind of job due to the complexity of its architecture. And I add, if you are not using ITCM memories and using cache, the execution will risk to be not deterministic.

[AScha.3]

From my tests :

20 MHz can get from H743 , at 480MHz , -O2, : 25ns hi or lo time ;

compared to cpu with "better" = direct access to port/bus : H563 , at 250MHz :

 4ns pin access, 16ns with while-loop : 82MHz output by pin toggling - not bad , i would say...

see:

https://community.st.com/t5/stm32-mcus-products/which-is-best-stm32-mcu-for-fast-driving-of-gpio/m-p/632729#M233727