Fetching Data with GPIOs

kostyak · ‎2008-02-17

Posted on February 18, 2008 at 05:27

kostyak · ‎2011-05-17

Posted on May 17, 2011 at 12:23

Hi !

Did anybody check how fast data can be read in through the GPIO ports ?

I have to read in 256 unsigned short values and store them in internal

ram at a rate of 8MHz. Is this possible with the stm32 clocked with 72MHz.

Is this also possible with the DMA ?

regards

Manfred

giles · ‎2011-05-17

Posted on May 17, 2011 at 12:23

I would have thought it would be fine as it can output at upto 50MHz.

don't know about the dma though haven't played with that

16-32micros · ‎2011-05-17

Posted on May 17, 2011 at 12:23

Hi all,

There is an interesting example in this application Note : ''AN2548'' Using the STM32F101xx and STM32F103xx DMA controller

: Section 4.3 : GPIO fast data transfer with DMA and also a source code is already provided :

, Hope this helps you , Cheers, STOne-32 ;)

tta · ‎2011-05-17

Posted on May 17, 2011 at 12:23

really good example !!

but how fast is the max external clock trigger in this example ?

the DMA need to be able to follow this and the program need to have a bit overhead also.

but 8MHz or even 20Mhz should be possible in 16 bits that is 40MBytes/sec peak.

I guess you will get problems at 30-40Mhz ?? or ??