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Question asked by Jedix on Feb 25, 2013
Latest reply on Mar 3, 2013 by Clive One

I use a STM32F4DISCOVERY, and I would like to begin to understant how the USB HOST/OTG works... ands it's not easy, there is a lot of files and lines of code.

I saw in ST examples, that in stm32f4xx.c there is

void TIM2_IRQHandler(void)

and then I saw that in usb_bsc.c it corresponds to the use of  "USE_ACCURATE_TIME". I would like to know what's are the consequences if I remove USE_ACCURATE_TIME and thus don't use the interrupt of TIM2. What is the purpose of the mecanism USE_ACCURATE_TIME ? I tried and it seems it still works, but is it less stable or reliable ?

In addition if you have some tips to learn how usb host/otg on stm32f4 works, I'll take it ! :)

Thank you !