stm32f407 GPIO maximum input frequency

[armindavatgaran]

Posted on January 03, 2015 at 19:07

Hello

What is the maximum gpio input frequency that cpu can handle in this family? 

[Tesla DeLorean]

Posted on January 03, 2015 at 19:17

What is the maximum gpio input frequency that cpu can handle in this family?

The limitation tends to come from the resynchronization of the pin input into the 84-90 MHz domain and the nyquist limit/effects that causes. You're interrupt/polling limits are likely to be much lower. You might do better restating you question by defining what it is you're trying to do, and what might be the practical limits on that?

[armindavatgaran]

Posted on January 03, 2015 at 19:35

Thanks for your answer , suppose that it should handle a 80 MHz parallel 8 bit A/D converter data and do some simple math operations .

Can DMA help to improve the frequency ? how ?Thanks.

[Tesla DeLorean]

Posted on January 03, 2015 at 20:21

DMA would save the processor work, and could be triggered by a TIM to provide a uniform timebase.

At 80 MHz your samples will be coming in far faster than you can do any processing on them. Determine how long your simple computation takes, as this will define a limit for your input rate.

[armindavatgaran]

Posted on January 04, 2015 at 05:37

It should take an average of each 4 data and send the 20 Mbps averaged data to host pc through some port like usb.

Will over clocking be a solution ?