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LMK61E2: Do we have any software template to configure LMK61E2

Wayne Wang20
Expert 4380 points
Part Number: LMK61E2
Other Parts Discussed in Thread: CODELOADER

Dear clocking experts,

One of our customer is evaluating LMK61E2. I wonder if you have some material to  help our customer configure LMK61E2 like:

1. Any software template or software example?

2. Any document to explain which registers are needed to be configured and the register sequence when configuring LMK61E2 to output at a specific frequency.

Best regards,

  • 0
    TI__Expert 8865 points

    Hello Wayne,

    We have a software to program the LMK61E2 . You can download it here:

    http://www.ti.com/lit/zip/snac074

    Best regards

    Puneet

  • 0 in reply to Puneet Sareen
    TI__Expert 4380 points

    Hi Puneet,

    Thanks for your reply.

    Do we have any reference coding in C langurage to help cusotomer program the device?

    What's more, the customer also wants to know the register programing sequence to configure the device to output a 40MHz signal.

    Best regards,

  • 0 in reply to Wayne Wang20
    TI__Expert 4415 points

    Hi Wayne,

    I do not have any raw reference code but I am attaching an Excel spreadsheet that summarizes the register writing and EEPROM programming sequence. Follow the instructions in the spreadsheet- essentially you copy paste the raw register data from the programming software that Puneet linked, and then it generates some pseudocode that explains which registers to write and in what order.

    I am also attaching a config file for the LMK61xx programming tool that has the settings needed for 40MHz LVPECL output. The file can be opened with the software and edited as needed, or if the settings are ok, the register data can be copied from the software to the Excel sheet.

    Regards,

    -Tim

    LMK61xx programming example.zip

  • 0 in reply to Tim Chao Li
    TI__Expert 4380 points

    Hi Tim

    If I understand correct, when a customer wants to know the register sequence and values to program the LMK61E2 to output a 40MHz LVDS signal, we need to do below procedure:

    1. In the LMK61xx Oscillator Programming Tool, set the Output Configuration to 40MHz and LVDS. Then click Generate Configuration.

    2. Export hex register values to a txt file.

    3. Use I2C to program LMK61E2 with the register sequence and values generated in No.2 step.

    Could you please help comment if I understand the procedure correct?

     

    Best regards,

  • 0 in reply to Wayne Wang20
    TI__Expert 4415 points
    Hi Wayne,

    Yes, this is correct.

    Note that this procedure will only program the device registers, not the EEPROM so the settings will be lost on power cycling. To write to EEPROM, the user must follow the steps outlined in the datasheet, section 8.5.5, 'Write EEPROM' on page 21.

    Regards,
    -Tim
  • 0 in reply to Tim Chao Li
    TI__Expert 4380 points

    Hi, Tim

    Customer said the register sequence generated in Codeload and LMK61xx Oscillator Programming Tool are different. I don't have the LMK61E2 EVM right now so could you please help check if below register sequence is correct for 40MHz LVDS output? I already applied for the EVM. I will help customer do moer test when I receive the EVM. Thank you

    Please see the register sequence customer used as below:

    R0 0x0010

    R1 0x010B

    R2 0x0233

    R8 0x08B0

    R9 0x0901

    R16 0x1000

    R17 0x1180

    R21 0x1502

    R22 0x1600

    R23 0x1773

    R25 0x1900

    R26 0x1A2E

    R27 0x1B00

    R28 0x1C00

    R29 0x1D00

    R30 0x1E00

    R31 0x1F00

    R32 0x2001

    R33 0x210C

    R34 0x2228

    R35 0x2303

    R36 0x2404

    R37 0x2500

    R38 0x2600

    R39 0x2700

    R47 0x2F00

    R48 0x3000

    R49 0x3110

    R50 0x3200

    R51 0x3300

    R52 0x3400

    R53 0x3500

    R56 0x3800

    R72 0x4802

    Best regards,

  • 0 in reply to Wayne Wang20
    TI__Expert 4415 points

    Hi Wayne,

    These registers are correct.

    CodeLoader and LMK6xxx programming tool should generate the same registers. Note that some registers will vary naturally depending on the state of the software (for example, register 48, NVMCNT, stores the number of times the EEPROM has been programmed. This register will vary depending on the EVM connected). This is normal and shouldn't matter. You can reference the register map in the device datasheet to verify that this is the case.

    Regards,

    -Tim

  • 0 in reply to Tim Chao Li
    TI__Expert 4380 points

    Hi Tim,

    The customer is testing our sample on their PCB board. When customer connects VDD to 3.3V and enables OE, there's no default 156.25 LVPECL output signal. Do you have any comment on this issue?

    What's more, the customer found that in one of our samples, the I2C address is changed to 0x0D which is not corresponding to our datasheet. Do you know any possible reason to make the I2C address changed?

    Best regards, 

  • 0 in reply to Wayne Wang20
    TI__Expert 4415 points
    Hi Wayne,

    How did the customer install the sample onto their PCB? Did they follow JEDEC standard 20 guidelines as recommended in the datasheet and in this app note: www.ti.com/.../spraby1.pdf

    Also, did they bake the parts if exposed to the environment for more than 168 hours (MSL level 3)?

    Our oscillators are extremely sensitive to moisture and solder temperature. These issues seem consistent with incorrect IC rework- I recommend that the customer try installing another sample following the guidelines listed above and baking the parts for 24 hours at 125C if needed.

    Regards,
    -Tim