How to improve the GPIO Frequency？

Dear all，

Now I want to use two gpios(as clock and data) to transfer a Bit-Stream.

I tested the gpio clock frequency is 1.7MHz with using write register mode to config it. But when I transfer the data using the clock, the gpio frequency will be reduced to 1.1MHz.

It is too slow for me. I need the gpio frequency as high as possible.

Does anyone have a good idea?

Thanks

chad