GPIOCLK_1 / Header pin 35 - how to use as CLKOUT


#1

Hi.

I need setup 25MHz / 16 MHz / 12MHz (variable) clock on SoC pin to provide it to the peripherals.
I’ve found GPIOCLK_1 pin on the 40-pin header (pin 35 - PWM_F).

How can I set GPIOCLK_1 pin to CLKOUT function and setup the required clock frequency on VIM?

Thanks in advance.


#2

Hi
The VIM1 GPIO PIN35 is PWM_AO_A, not the PWM_F as you said. And the GPIOCLK_1/PWM_F is PIN39 not PIN40, well, you confuse me a lot :wink:

Is it possiable for you to use external crystal to setup the clock for your purpose, we haven’t check the clock output from the GPIOCLK_1/PWM_F yet :wink:

Have fun!


#3

I cannot use external crystal for our peripheral PCB (which is stepper motor sync).
We need to provide 16 MHz sync clock from the SoC.

So, possibly, you can check the clock output from GPIOCLK_1 and give some info on this.

Thanks in advance.


#4

Hi again.

Can anyone from Khadas staff explain how to set GPIOCLK_1 (CLK25 // pwm_F // CLKOUT) pin (which is pin 35 from 40-pin GPIO HEADER) to CLOCK function?

It’s completely unclear from the existing datasheet how to set this pin to work as clock out and how to configure clock frequency… Possibly you can ask amlogic support for some information on the issue.

Thanks in advance.