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How Much is the Maximum Speed of GPIOs in Cubieboard 2

Started by hamidreza, August 12, 2014, 04:14:08 pm

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hamidreza

Hello All,

How much is the maximum speed one can get from GPIO pins in Cubieboard2. I have tried several C codes that can access (write) into memory address of the GPIO pins, but I could not get the speed more than 2MHz. Is there anybody who could get a more speed over GPIOs?

I need the speed of 12 Mhz and so I will be very thankful if someone can share experiences..

mMerlin

On an A20-OLinuXino-MICRO-4GB board https://www.olimex.com/Products/OLinuXino/A20/A20-OLinuXino-MICRO-4GB/ I got to just under 8 MHz bit-banging a port through mmap.  Same chip, I think the same speeds.  Solid 8MHz running standalone code.

After configuring all pins of PI to be outputs:
    volatile uint32_t tstVal = 0;
    while(true) {
      tstVal ^- 0xffffffff;
      *PI_Data = tstVal;
    }
--ĀµMerlin