How fast is GPIO

How fast GPIO can be? Is it possible to store 8bit data stream clocked by 27MHz clock signal to the memory, for example?


Perhaps, but... it depends on details. Are you going to sample the clock
or using the clock to latch the data into BBB input registers? You probably
need to use PRU rather than the main CPU because at this speed there
wouldn't be much left for other OS functions. You have to be careful about
managing memory: how long to you want your capture to run? 30MB/s is
basically what you get from mass storage, but with BBB 512MB memory, you'd
completely fill it in a couple of seconds. Do you watn to capture and
store? capture and process?

In other words, more detail, please.

take a look at the "beagle logic" project:

ready to go image:


Capture and store the data, that are changing at falling edge of 27MHz clock and stable at rising edge.
Few megs burst is enought, continuous capture is not needed.