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UCD90120A: Do I need to erase the UCD90120A when re-programmed the chip?

Part Number: UCD90120A

Hi guys,

Do I need to erase the UCD90120A when re-programme the chip? If no, would it cause any problem to the functionality of the power sequencer IC?

Could I generate the erase file in spv? I need to do the erase and program using the ASSET JTAG boundary scan. 

For my second question, if I generate my own spv file to blank the power sequencer, would it causing any problem or damage to the IC? I am using the JTAG path. 

Hopefully will get the reply as soon as possible from you guys. Thanks. 

Regards,

hong wei

  • Hi Hongwei,

    Sorry for the late reply. We will have someone to answer your question quickly.

    Thanks
    Qian
  • 1. Importing configuration file: if you import data flash file (.hex) then yes. You will need to disable the "data flash write-protect bit", then erase the data flash, then write the all FFs data. These steps are done using Fusion GUI. If you import the project file (.xml), then erasing data flash is optional. When import the configuration using project file (.xml, PMBus commands), depends on the current configuration loaded on the device, the new configuration will be loaded to the device, and your system, some faults and response-to-fault might occurs and might cause some problem. 

    2. Don't know the spv format. However, you can use Fusion GUI to export the data flash script file (.csv) (It is a steps by steps to import the data flash to device), and convert to the spv format.

  • Hi Anne Ngo77,

    Sorry for confusing...I want to export the config data in Data Flash SVF/JTAG format...because I am using the asset boundary-scan tool to program the power sequencer via JTAG path instead of going through PMbus. So my question is, do I need to create any erase file for it before I program the power sequencer with the SVF file that I generated from the fusion tools? Currently, my project is in the development stage...so I have some modification on the SVF file and need to re-program the power sequencer, so each time I re-program the power sequencer, do I need to erase the file first? Thanks.

     

  • JTAG specification is not an industry controlled standard, and is sometimes implemented slightly differently by each ICT manufacturer,

    and JTAG programming are directly accessing the memory space without any protections against writing the wrong memory location.

    Therefore we do not recommand JTAG programming and istead we highlight recommend to use I2C/PMBus method to program the device.

    Regards

    Yihe

  • Hi Yihe,

    Thanks for your reply. But do we need to erase the chip if using the JTAG? Is the SVF file generated from the fusion tool consists of erasing script? 

    Rgds,

    hong wei

  • Hello

    You do not have to erase since it is part of the svf script file, but as said, we do not recommend JTAG  programming. if you are facing any JTAG programming issue, it would be very difficult to support.

    Regards

    Yihe 

  • Thanks for your clarification. But recently I am using the JTAG method for power sequencer IC programming, I found that 3 out of 6 boards, the JTAG path was broken, not able to detect/program the IC via JTAG path...However, the IC is able programmed via I2C/PMbus, and able to function properly...so my questions here, could the programming via JTAG path causing the JTAG path broken?
  • Hi
    As explained in the early post, JTAG is not a standard and it is up to how the JTAG vendor. We do not recommend JTAG due to this fact.

    The JTAG can be enableld only on the following two cases.
    1. the device has no valid configuration
    2. the device is fixed at 126 pmbus address.

    Please refer UCD90120A data sheet for details.

    Again, I2C/PMBus program is always recommended.

    Regards

    Yihe
  • Thanks, Yihe. 

  • Hi Yihe,

    as per you've mentioned that JTAG is not recommended to program the power sequencer & we are aware of it already. So assuming a case whereby device has been pre-programmed via JTAG & if functionality is not per expectation then flashing again via PMBUS or I2C would set the device back to predefined states? Would direct access to device memory via JTAG bring potential issues such as causing physical damage to device?
  • Hi Leo
    Most case, the device can be restored via i2c programming, but under some very rare case, the JTAG programming may brick the device which need return to TI assemble site for re-test to recover.

    Regards

    Yihe