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TPS65218D0: Writing to EPROM and power sequence

Part Number: TPS65218D0
Other Parts Discussed in Thread: TPS65218, TPS6521815, IPG-UI, TMUX7413F, TPS65218EVM-100, BOOSTXL-TPS65218

Hi All,


I have a question about TPS65218D0.

I want the power sequence to be in the following order
DCDC1 -> DCDC2 -> DCDC3 -> DCDC4 -> VLS1
Please tell me how to set this up.

I want to write to EPROM with no voltage output.
Is there a way to do this?
The reason is that I do not want to input the voltage before changing the setting to FPGA.


Best Regards,
Ishiwata

  • Hi Ishiwata,

    Our TPS65218 expert is out of office. Please expect a response early next week.

    Thanks,

    Daniel W

  • Hi Daniel,

    Thank you for your reply.
    We look forward to your reply.

    A customer tried to write to the EEPROM, but was informed that it could not be written correctly.
    VIN_BIAS will be a stable 4.5V. Please let me know what could be the reason.
    Or is it not possible to write to EEPROM with I2C to TPS65218D0?

    Please answer this question first from the first question.

    Best Regards,
    Ishiwata

  • Hello Ishiwata, 

    Thank you for your patience. Firstly let me highlight a note from page 48 of the TPS65218D0 datasheet. "Changing the power-up default values is not recommended in production but for prototyping only." For complete configuration flexibility TI recommends using the user programmable version of the device TPS6521815.

    Please see my comments below in regards to your questions. 

    I want the power sequence to be in the following order
    DCDC1 -> DCDC2 -> DCDC3 -> DCDC4 -> VLS1
    Please tell me how to set this up.

    Yes this can be done via I2C. The image included below from page 23 of the datasheet summarizes at a high level how to change the power up sequence via I2C. 

    You will need to write to SEQ1 through SEQ7 registers (described on datasheet pages 81 to 91) and assign DCDC1 to strobe 3, DCDC2 to strobe 4 and so on. Using these registers you can also set the desired delay for your sequence. Do not use strobe 1 and strobe 2 as they are dedicated for DCDC5/6.

    Please keep in mind that these registers are password protected. You will need to follow the instructions for writing a protected register on page 50 and included below.

    Once you have correctly written all the sequencing registers you will need to consecutively write 0x50, 0x1A, then 0xCE to the password register (address 0x10 hex) to commit your settings to the EEPROM as new defaults. 

    I want to write to EPROM with no voltage output.
    Is there a way to do this?

    When you first power on the device the predefined power-up sequence will occur. After this you can disable all output rails via I2C using ENABLE1 and ENABLE2 registers (address 0x11 hex and 0x12 hex). 

    VIN_BIAS will be a stable 4.5V. Please let me know what could be the reason.

    Your customer should be able to write to EEPROM with I2C on this device.

    Can you have your customer read the VPRG bit in the INT1 Register (address 0x1 hex) when they attempt to write? The acceptable input voltage must be between 4.5V and 5.5V for EEPROM programming. If there is a voltage drop between their power source and the device the input voltage may be too low for programming. 

    Regards,

    Garrett 

  • Hello Garrett,

    Thanks for your reply.

    Regarding the writing to INT1 in your answer below, what is the timing?

     " Can you have your customer read the VPRG bit in the INT1 Register (address 0x1 hex) when they attempt to write? "


    Before writing to the password register, but after?


    Best Regards,
    Ishiwata

  • Hi Ishiwata, 

    The correct timing is to first attempt to commit the current register settings to EEPROM memory by consecutively writing 0x50, 0x1A, then 0xCE to the password register (address 0x10 hex). Then read INT1 register after waiting a short period of time (approximately 100 msec) for the EEPROM programming to complete. 

    The status of the INT1 register will tell you if the input voltage was too low (bit 5 = 1) or if the programming was successful (bit 0 = 1).

    Best Regards,

    Garrett

  • Hi Garrett、

    Thank you for your reply and support.

    A customer contacted me.
    I found that I was using the TPS65218B1 instead of the TPS65218D0 for verification.
    The reason for using the TPS65218B1 is for FPGA evaluation.
    The TPS65218B1 is not used in production.
    Is the TPS65218B1 writable to EEPROM? Please tell me how to do that if possible.

    Best Regards,
    Ishiwata

  • Hi Ishiwata, 

    Programming the EEPROM on TPS65218B1 should be the exact same as programming on the TPS65218D0. Please have the customer follow the instructions I have described in my previous responses. 

    Best Regards,

    Garrett

  • Hi Garrett、

    Thanks for the answer.

    The customer has performed the same programming, but says they cannot write to the EEPROM.

    I may not understand yet. And I may have overlooked your answer.
    Do I need to take password protection steps before writing to the password register (write of 0x50, 0x1A, or 0xCE to 0x10)?


    Do you have any advice? Please tell me how to check.


    Also, Customer is considering TPS6521815 at the same time

    The customer informed me that the default setting voltage is applied to the FPGA at startup because it cannot be written with I2C unless PWR_EN is set to High.

    Is it possible to write to EEPROM or set voltage to DCDC1/2/3/4 via I2C without setting PWR_EN to high?


    Thank you for your support.

    Best Regards,
    Ishiwata

  • Hi Ishiwata, 

    Do I need to take password protection steps before writing to the password register (write of 0x50, 0x1A, or 0xCE to 0x10)?

    No, the password register itself is not password protected.

    The correct steps are as follows.

    1)Set registers to desired values. Password protected registers require you to follow the steps in section 5.6.1 to change the value from its default setting. These steps are 1) write register address to password register (ex write 11 hex to access ENABLE1) 2) write 7D hex to password register 3)write your desired setting to the register address you previously wrote to the password register. 

    2) Consecutively write 0x50 hex, 0x1A hex, then 0xCE hex to the password register (address 0x10) to program the current register settings to the EEPROM memory.

    If by change they are using our provided GUI tool IPG-UI, which is located on the TPS65218D0 product page and linked here: https://www.ti.com/tool/IPG-UI then they can utilize the the auto password and program features. The auto password feature allows the GUI to unlock protected registers so the customer does not need to follow the steps in datasheet section 5.6.1. The programming feature then programs the values to EEPROM memory with the click of a button. 

    Is it possible to write to EEPROM or set voltage to DCDC1/2/3/4 via I2C without setting PWR_EN to high?

    No, PWR_EN should be high. The reason is that PWR_EN to low is a trigger to power down the PMIC. The device must be in active state to write to EEPROM and set regulation voltages. 

    Has the customer read from INT1 register after attempting to program EEPROM as I suggested earlier? Knowing this status will help to determine why they cannot successfully program EEPROM. 

    Regards,

    Garrett 

  • Hi Garrett、

    Thank you for your answer about PWR_EN of TPS6521815.

    Is there a way to change the settings before the default voltage is output?
    I would like to propose a switch IC between the TPS6521815 and the FPGA. Do you have a recommended switch IC for the TPS6521815?
    I'm thinking of proposing the TMUX7413F, but is it over-spec?

    Thank you for contacting us about the procedure for writing to the EEPROM. Thank you for your support.
    We asked the customer to read INT1 again. I would like to wait to hear from the customer.


    I appreciate your kind support every day.


    Best Regards,
    Ishiwata

  • Hi Ishiwata, 

    Let me clarify something on the TPS6521815. This device is user programmable and comes with the majority of its register settings "blank." This is the key difference between the TPS65218D0 and TPS6521815. I have confirmed no output rails should power on by default on the TPS6521815 unless the customer has already made changes to the defaults and saved to EEPROM memory.

    The factory settings have all outputs initially disabled. This is shown in the register map section (section 8.6) of the TPS6521815 datasheet. Specifically, ENABLE1, ENABLE2 and SEQx registers show all outputs are initially disabled and not controlled by the power up sequencer.

    Is there a way to change the settings before the default voltage is output?

    If the customer is using a new TPS6521815 they should be able to change the settings and save to EEPROM memory without ever having output rails to FPGA turn on. Therefore, there should be no need to utilize a switch between TPS6521815 and the FPGA. 

    Best Regards,

    Garrett 

  • Hi Garrett、

    Thanks for your answer.

    A customer has a question about the TPS6521815.

    TPS6521815 means that all registers are disabled, so
    The customer wants to confirm the registers required for booting.
    There is a request for reference data for register settings required for I2C. Please provide reference data for the required registers.


    In addition, there was a request to evaluate with EVM.
    Do you have an EVM for the TPS6521815? I checked the product page and found a TPS65218EVM-100 with a TPS65218D0 on it.
    If I want to evaluate the TPS6521815, how should I evaluate it?


    I appreciate your support every day.


    Best Regards,
    Ishiwata

  • Hi Ishiwata, 

    I do not quite understand the questions about "registers required for booting" can you please rephrase? Required for booting what device, the TPS6521815?

    All register defaults are defined in the register map section of the TPS6521815 datasheet, which begins on page 46, and no register settings need changing to access I2C on this device. I2C can be accessed as long as there is input power applied and PWR_EN is high. 

    TPS6521815 means that all registers are disabled,

    No, registers values are defined so that output rails are disabled, but the registers themselves are not disabled in any way. 

    Do you have an EVM for the TPS6521815?

    There is no dedicated EVM for the TPS6521815. If the customer wants to evaluate the TPS6521815 they can either replace the TPS65218D0 with a TPS6521815 on the TPS65218EVM-100 or they can evaluate using the socket board BoostXL-TPS65218 linked here: BOOSTXL-TPS65218 Evaluation board | TI.com

    Regards,

    Garrett