CDCE62002EVM: CDCE62002EVM Locked board led always off and abnormal register value on power up

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Replies: 4

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Part Number: CDCE62002EVM


I am trying CDCE62002EVM and I am having the following issues:

1. The registers value after cycling the power from software is as attached.

I am loading the default settings and writing them to eeprom and yet still the same old values getting loaded on power up.

2. No matter which settings I use, the on board locked is always off even if the status on gui hows on.

I am powering the board from usb and using the on board crystal as reference, the clock outputs are floating.

the frequencies I want to generate are 100 MHz and 25 MHz both lvcoms.


4 Replies

  • Hi Mahmoud,

    First of all, does everything work before registers are written to EEPROM? And then how did you write to EEPROM? There's a button "EEPROM Write + Lock". You can also try manually writing to EEPROM as instructed in datasheet

    From what I recall that onboard LED is not indicating lock status properly. You can either measure the voltage level on pin PLL_LOCK or read back the register value of R2[6]. Refer to datasheet 9.3.6 for more details.


  • In reply to Hao Z:

    Hi Hao,

    Thanks for your reply.

    I didn't check the outputs yet as I don't have access to scope currently.

    I was using EEPROM Write command, I have tried EEPROM Write + Lock and it seems keeping the settings now.

    What is the difference between the EEPROM Write  & EEPROM Write + Lock ? it seems there is no use for EEPROM Write?

    I have checked the voltage on the locked pin and it is reflecting what I am seeing on the gui.

    I have noticed the led is not directly connected to the CDCE chip, it is connected to the on board controller which seems not working as expected.

    Is there any firmware upgrade for the on-board controller?



  • In reply to Mahmoud Zannerni62:

    I have just noticed the follwoing from CDCE eval board data sheet.

    "Note that the CDCE62002 does have a permanent EEPROM lock mode. After this mode is selected the EEPROM within the CDCE62002 cannot be changed. This is useful when setting final configurations."

    The EEPROM in this case my CDCE is permanently locked? why it was not keeping the settings when not using the locked command?



  • In reply to Mahmoud Zannerni62:

    Hi Mahmoud,

    Sorry I didn't realize there was such thing as "permanent lock". I thought it was to lock the EEPROM so that the EEPROM is protected from accidental corruption, just like any other device. I didn't find any description on this permanent lock in the datasheet, and so far I'm not sure how it works. 

    Are you still able to change EEPROM settings after clicking that "EEPROM + lock"?