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LMK03328: How long does a transfer of registers to SRAM take?

Part Number: LMK03328

I'm developing some code to program device settings into EEPROM page 0 on the LMK03328.

Writing the registers is successful (the required output frequencies appear at the two outputs we are using). However the setting don't appear to be saved in EEPROM, despite the EEPROM write count being incremented.

We are leaving much greater than the recommended 230ms for transfer of SRAM data to the EEPROM, but how long does a transfer of registers to SRAM take? We are possibly not waiting lng enough for the register settings to be transferred to the SRAM before starting the write to EEPROM.

Can R137 be read during this time to check for completion of the transfer to SRAM (or will this abort the process)?

  • Hello,

    230ms is a sufficient time. R137.2 can be read to check if the EEPROM programming is still active.

    When writing make sure that you committed the register settings to the correct SRAM page (REGCOMMIT_PG - R145[3:0]) and that GPIO[3:2] are set correct.

    Also check if R137.5 will result in a 1. That might indicate a false EEPROM write.

    Regards,

    Julian

  • Hello Julian,

    Thanks for your response.

    Can I just confirm:

    We currently have allowed about 10µs for the register transfer from the registers to the SRAM. After that we allow 230ms for writing SRAM to EEPROM.

    Are you recommending that we should allow 230ms for the register transfer to SRAM and another 230ms for the SRAM write to EEPROM?

    I know writing to EEPROM is a slow process, but writing to SRAM should be considerably faster. Unfortunately, the datasheet doesn't provide any timing  information for this transfer to SRAM.

    Regards,

    Peter

  • Hi Peter,

    we don't have an exact timing for the register to SRAM transfer time. I would give it a 100us.

    Let me know if that works. Please also double check if the GPIOs are set correctly.

    regards,

    Julian

  • Hi Julian,

    I tried allowing 100us for the transfer to SRAM as you suggested and we can now program the EEPROM successfully.

    Thanks you for you help.

    Regards,

    Peter