STM32F746 slower then STM32F407???

[Evgeny Popov]

Posted on June 20, 2018 at 13:46

As i had lack of speed while using stm32f407 disco, i ordered stmf746 nucleo-144. And What suprised me was that it is slower then stmf407, despite that stm32f07 168 max mhz, and stmf756 is up to 216Mhz. I configured my code with CUBEMX. Simple test: 

While(1)

{

HAL_GPIO_WritePin

(GPIOD, GPIO_PIN_12, GPIO_PIN_SET);

HAL_GPIO_WritePin

(GPIOD, GPIO_PIN_12, GPIO_PIN_RESET);

}

gives me 150ns pulses on STM32F746

when the same test gives me 100ns on STM32F407.

I used HSE 8mhz external resonator. Aclually clock config were the same for both mcu, except that 

STM32F746 has 216 mhz max when stmf407 168.

So why is that? STM32F746  should be more powerful. Also it was released later

#stm32f407 #stm32f746 #external-rc

[Evgeny Popov]

Posted on June 21, 2018 at 07:39

Hi, well ,as you can see clock config images above, sysclock is on max freq, also my code doesnt do any other tasks besides toggling a pin with HAL struct

[waclawek.jan]

Posted on June 21, 2018 at 16:41

Im not sure what do you mean by '

switching on compiler optimization'

Read the manual to your compiler/toolchain. Surely there is a mention of optimization.

JW