i.MX ProcessorsのトピックHow to speed up GPIO

How to speed up GPIO

tiejunhe — Fri, 15 May 2015 11:12:35 GMT

Hi everyone, I'm working on iMX515, My linux driver has 3 statements :

gpio_set_value(pin,1);

gpio_set_value(pin,0);

gpio_set_value(pin,1);

Then ,I can get a negative pulse which pulse width is about 320ns. It seems too slowly, How can I speed it up?

igorpadykov — Fri, 15 May 2015 16:10:29 GMT

Hi tiejun

one can write small subroutine on assembler for faster access, also it may be

recommended to have L2 cache enabled and the MMU, then try to find the entry

that corresponds to the area where the GPIO registers are mapped and set the

bufferable field for that particular mmu entry.

Best regards

igor

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tiejunhe — Sat, 16 May 2015 14:14:03 GMT

Thanks,I use your method,and get a negative pulse which width is about 80ns.