• State
  • Locked Locked
  • Replies 2 replies
  • Subscribers 99 subscribers
  • Views 455 views
  • Users 0 members are here
Support feedback
Options
Options
Related

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

clock pulses generation using gpio

Francis Kumar
Expert 1330 points
Other Parts Discussed in Thread: AM1808, OMAP-L138

Hi,

 

We missed out one synchronized signal for LCD in AM1808 circuit. Instead of that we are generating the 

pulses(delay) using GPIO. How to generate contiunous clock pulses on gpio. We want to gnerate the gpio

ON pulse(56usec) and gpio OFF pulse(6usec). Is there any reference to enable this feature in kernel level

using Timer based or etc..Is it possible to develop the code in bootloader itself. 

 

How do i achieve usecs pulses using gpio?

 

Regards,

Francis Kumar

  • 0
    Prodigy 60 points

    Hi,

    in the OMAP-L138 there is a PRU (Programable Realtime Unit) which can create even complex Signals an SPI.

    It should be able to generate this clock signals.

     

    I don't know if this PRU is in the Am1808, but i think you should take a look.

    I'm not shure if the PRU could set any GPIO or only some of them, because we do not use it in the moment. You schuld read about this carefully.

     

    regards,

     

    Stefan

     

  • 0
    TI__Intellectual 880 points

    Hi Francis,

                        You need one continous Pulse of 62uS (ON pulse(56usec) and gpio OFF pulse(6usec) )time with Duty Cycle of approx 90.3%.

                         You can genarate this type of Signal using GPIO 2 way accurately ------

    1.                Enable the timer interrupt  with configure the timer resister value 56uS & 6uS . Toggle the GPIO port & Reload the two value sequentially in ISR.

    2.                If PWM Module I/O is free for access then Configure the PWM Peripheral with approx 16.13KHz with 90 % duty cycle.

     

    Regards

    Abhijit