If you control a GPIO pin from a high level language via the linux-system-file-io, you can toggle the pin at about 6 kHz maximum.
If you control a GPIO pin directly from a language like "C", you can toggle it at about 4 MHz, maximum. If you control a GPIO pin from the PRU, you can toggle it at about 200 MHz maximum. In each case, maximum is a simple program that just says HI, LOW, HI LOW, HI, LOW, etc. Any additional program, will slow it down, some. --- Graham == On Tuesday, July 28, 2015 at 12:07:51 AM UTC-5, 멘지 wrote: > > thanks for reply > > Put the clock in the camera comes out give data.(8bit) > > > So I made read clk and recived data. > > However, the speed of reading data from a GPIO through the mmap was slow > to solve the problem, but a problem occurred a slow in clock speed makes > the BeagleBoard > > So I have such a question. > > > > 2015년 7월 28일 화요일 오전 3시 43분 44초 UTC+9, Karteek YV 님의 말: > >> Use PRU to read/write I/O pins which can be done in 5ns. I don't >> understand how you want read data through GPIO pins from a camera. >> >> On Monday, 27 July 2015 10:37:15 UTC+5:30, 멘지 wrote: >>> >>> Sorry Sorry .... >>> >>> I am doing a project using the camera. >>> >>> but ,The first method is to receive data rate is too slow. >>> >>> GPIO_HIGH(); >>> GPIO_LOW(); <-- Userspace coding >>> >>> So ,I hope come to read the data a little more quickly. >>> >>> can someone help me? >>> >>> >>> >>> >>> 2015년 7월 27일 월요일 오전 6시 55분 21초 UTC+9, William Hermans 님의 말: >>> >>>> Well, this question is a bit like asking "How do I make a car?" >>>> >>>> On Sun, Jul 26, 2015 at 1:09 PM, Karteek YV <[email protected]> wrote: >>>> >>>>> which type of clock? >>>>> >>>>> On Sunday, 26 July 2015 18:14:59 UTC+5:30, 멘지 wrote: >>>>>> >>>>>> How do I create a clock? >>>>>> >>>>>> I was use vi editer (user space) >>>>>> >>>>>> GPIO_HIGH(); >>>>>> GPIO_LOW(); <-- SO I has used but it is very slow .... >>>>>> >>>>>> So, i want to create clock in BBB >>>>>> >>>>>> How do I create a CPU clock? >>>>>> >>>>> -- >>>>> For more options, visit http://beagleboard.org/discuss >>>>> --- >>>>> You received this message because you are subscribed to the Google >>>>> Groups "BeagleBoard" group. >>>>> To unsubscribe from this group and stop receiving emails from it, send >>>>> an email to [email protected]. >>>>> For more options, visit https://groups.google.com/d/optout. >>>>> >>>> >>>> -- For more options, visit http://beagleboard.org/discuss --- You received this message because you are subscribed to the Google Groups "BeagleBoard" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. For more options, visit https://groups.google.com/d/optout.
