topic Re: i.MX6S CLKO1 does not output 32kHz. in i.MX Processors

i.MX6S CLKO1 does not output 32kHz.

satoshishimoda — Wed, 19 Mar 2014 06:30:05 GMT

Hi community,

I have a question about i.MX6S CLKO.

I tried output 32kHz from CCM_CLKO1 with the following settings.

However, it does not output even though external 32kHz crystal oscillates certainly.

=====

IOMUXC_SW_MUX_CTL_PAD_GPIO05 = 3; (Select CCM_CLKO1, SION=0)

IOMUXC_SW_PAD_CTL_PAD_GPIO05 = 0x0001B0B0;

CCM Clock Output Source Register (CCM_CCOSR)

8 CLK_OUT_SEL ： 0 CCM_CLKO1 output drives CCM_CLKO1 clock

7 CLKO1_EN ： 1 CCM_CLKO1 enabled.

6-4 CLKO1_DIV ： 000 divide by 1(default)

3-0 CLKO1_SEL ： 1110 ckil_sync_clk_root

=====

[Q]

Is any additional setting needed to output 32kHz from CCM_CLKO1?

If no additional setting is needed, could you let me know what is considered as a possibility of a root cause?

For your information, 24MHz is output from CCM_CLKO2 with similar setting as above.

Best Regards,

Satoshi Shimoda

Re: i.MX6S CLKO1 does not output 32kHz.

satoshishimoda — Wed, 26 Mar 2014 04:19:27 GMT

Can anyone reply me?

Re: i.MX6S CLKO1 does not output 32kHz.

Yuri — Wed, 26 Mar 2014 06:17:15 GMT

Is CLKO 32 KHz output just a DC level or some waveforms (which look as some kind of noise) may be observed ?

Re: i.MX6S CLKO1 does not output 32kHz.

satoshishimoda — Wed, 26 Mar 2014 09:42:10 GMT

Hi Yuri,

I'm checking it to measurement member.

Just a moment please?

Best Regards,

Satoshi Shimoda

Re: i.MX6S CLKO1 does not output 32kHz.

AnsonHuang — Thu, 27 Mar 2014 03:14:48 GMT

I just tried it on i.MX6DL sabresd board, and CLKO1 can output 32KHz clock. Below is the config

r159 on i.MX6DL SabreSD board, pin GPIO_0

0x20e020c set to 0 to select it as CLKO1;

0x20e05dc set to 0x1b0b0;

0x20c4060 set to 0x8e to select ckil sync clock output.

Then there will be 32KHz clock output on r159.

I also tried GPIO_5 pin, set 0x20e0230 to 3, we can see 32KHz clock on r66 of i.MX6DL SabreSD board.

Re: i.MX6S CLKO1 does not output 32kHz.

satoshishimoda — Thu, 27 Mar 2014 04:26:35 GMT

Hi Yuri, Yongcai,

Thank you for your cooperation.

I got a report from measurement member about root cause.

It was a board pattern issue, the pattern was cut by high temperature.

So now, 32kHz is output correctly from CLKO1 on other board that has no pattern issue.

I appreciate your great support!