i.MX ProcessorsのトピックRe: CCM_ANALOG_MISC2 cannot be configured

CCM_ANALOG_MISC2 cannot be configured

chrisolarti — Wed, 22 Apr 2015 23:27:20 GMT

Hi Freescale,

I am trying to use the CCAM_ANALOG_MISC2:AUDIO_DIV_MSB, AUDIO_DIV_LSB so I can divide the PLL4_AUDIO clock (pll4_main_clock) from 688.128MHz to 86.016MHz. I can verify the PLL4_AUDIO is reaching to 688.128MHz when using CCM_ANALOG_PLL_AUDIOn:DIV_SELECT=28, CCM_ANALOG_PLL_AUDIO_NUM=672, CCM_ANALOG_PLL_AUDIO_DENOM=1000. This is following equation with Fref=24MHz:

I can also verify the CCM_ANALOG_PLL_AUDIOn:POST_DIV_SELECT=0 (divide by 4) is working to give a pll4_main_clock=172.032MHz. However, when trying to configure CCM_ANALOG_MISC2:AUDIO_DIV_MSB & AUDIO_DIV_LSB to divide by 2:

I do not see the pll4_main_clock=86.016MHz.

My observation is using CCM_CCOSR:CCM_CLKO1 to use PLL4_MAIN_CLK as the source clock with a divider by 1.

I also took note in CCM_ANALOG_MISC2:AUDIO_DIV_MSB where the: output clock of the audio PLL should be "gated" prior to changing this divider to prevent glitches. However when configuring CCM_ANALOG_PLL_AUDIOn:POWERDOWN=1 during ENABLED=1/BYPASS=1, I am unable to get the PLL to enter a DEACTIVE HIGH STATE, which should make the PLL "gated".

I tried with with CCM_ANALOG_PLL_VIDEO and that seems to be working fine.

My order for switching PLL speeds at reset:

1. BYPASS = 0 --> (POWERDOWN will remain = 1 & ENABLE will be = 0)

2. CONFIGURE PLL DIV_SELECT, NUMERATOR, DENOMINATOR, MISC2

3. ENABLE = 1

4. POWERDOWN = 0

5. WAIT WHILE CCM_ANALOG_PLL_AUDIO:LOCK = 1

Is there anything else that I am missing when trying to "gate" PLL4_AUDIO? Or is PLL4_AUDIO is unable to be "gated" since there is no CCGR for pll4_main_clk?

Thanks in advance.

Chris.

Re: CCM_ANALOG_MISC2 cannot be configured

igorpadykov — Tue, 28 Apr 2015 00:09:49 GMT

Hi chris

suggest also to try "10" - divide by 1

and use for that i.MX 6Series Platform SDK

and look at EB790 Configuration of Phase Fractional Dividers

Best regards

igor

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Re: CCM_ANALOG_MISC2 cannot be configured

bonzo — Fri, 24 Jul 2015 18:09:51 GMT

See this post. https://community.freescale.com/thread/328512?q=PLL4%20AUDIO_DIV

It seems that for iMX6D/Q, "CCM_ANALOG_MISC2n[MSB:LSB]" divider does NOT exist.

Re: CCM_ANALOG_MISC2 cannot be configured

igorpadykov — Sat, 25 Jul 2015 08:30:56 GMT

Thanks Bradley for pointing on that !

Best regards

Igor

Re: CCM_ANALOG_MISC2 cannot be configured

chrisolarti — Fri, 20 Nov 2015 01:22:43 GMT

I am unable to access that link. Can I have privileges to review?

Thank you.

Chris.

Re: CCM_ANALOG_MISC2 cannot be configured

bonzo — Fri, 20 Nov 2015 17:53:12 GMT

See attached.

Brad

Re: CCM_ANALOG_MISC2 cannot be configured

keitanagashima — Mon, 18 Apr 2016 05:15:25 GMT

Dear Bradley,

Hello. My customer faced the same issue (i.e. He wasn't able to configure the AUDIO_DIV_LSB and MSB).

(Device : i.MX 6Quad)

You said ; CCM_ANALOG_MISC2n[MSB:LSB]" divider does NOT exist.

Really?

I checked the latest reference manual and chip errata today.

But, the related description wasn't found!

Best Regards,

Keita