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LMK05318B: problems with PLL lock in customer board

Paul Stevens
Intellectual 1065 points
Part Number: LMK05318B

Tool/software:

Hi, this was initially supported by Jennifer Bernal over email, switching to E2E as requested.

I have included the previous email thread:

Not sure if this forum is internal so have removed customer details.

Yes, I have tried to toggle the R12[7] but it doesn’t seem to help. And the issue is the same regardless of the configuration, whether it is downloaded from the EEPROM or by writing register values to the LMK05318B.

I also tested toggling the R12[7] with the EVM and the issue is also same on that board. I have programmed the EEPROM of the LMK05318B EVM and after power up I toggle the R12. Some of the output clocks are working and some are not. Only when I write all registers with the TICS Pro, the all output clock are up and running.

BR

 

From: Stevens, Paul <p-stevens@ti.com> (from CTS Apps)

Hi,

Can you try issuing a soft reset (toggle R12[7])? The reset must be issued after boot when the APLL registers have been updated.

The soft reset bit performs a PLL calibration to ensure the APLL can lock. Without this, the APLL may not lock after boot and the outputs remain muted, hence no output is seen.

Paul.

From: customer: 

Hi, I’m having an issue with configuring the LMK05318B device located in my hardware. My HW does not support straight TICS Pro connection so I have to implement the TICS Pro configuration file to the SW which the HW is using.

I have created and tested my configuration with TICS Pro and LMK05318BEVM but when I run the configuration in to my HW, the outputs of the LMK05318B are working randomly, sometimes all or some of the output clocks are working as should and sometimes none of the output clocks are working. I have noticed that if I ran the configuration twice in a row then all output clocks are working. And an another solution is to toggle bit 6 (SYNC_SW) of the register R12 (0xC). I have exported configuration file with two different ways, first one created with TICS Pro by using File -> Export hex register values and an second one Export EEPROM Instructions from the LMK05318B EEPROM page.

So my question is, why I’m not able to get all output clocks working without running configuration file twice or toggling the SYNC_SW bit?

  • 0
    TI__Intellectual 1170 points

    Hello Paul,

    I can help answer questions as Jennifer is out of office.
    When the device first powers up it will load the contents programmed into the EEPROM as the active registers and configuration.
    After programming a new configuration to the device it is necessary to perform a reset. When a new configuration is loaded into the device while it is operating, even though the registers changed the part may be generating incorrect frequencies and be stuck in the previous state. This is why you need to perform the reset to ensure the device is starting from the correct state.

    From what I understand the two solutions would be to add the reset bit writes to the end of the programming sequence of the part or to program the EEPROM so the device always starts-up in the correct state.

    Please let me know if you have any additional questions or if I misunderstood the information.

    Best Regards,

    Kyle Yamabe