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DP83TG720R-Q1: DP83TG720R-Q1

Jing Liang
Prodigy 160 points
Part Number: DP83TG720R-Q1


Tool/software:

Hello Expert，

I read 0x456h register value is wrong, may I know why? The 720R VDDIO is 3.3V, and the J10 power I apply is 2.1V. Can i change to 3.3V? pls check if anything wrong.

setup:

  • 0
    TI__Mastermind 18950 points

    Hi Jing,

    0x0227 is not the readback I would expect from this register. Some notes and questions:

    • What board is the DP83TG720 being tested on?
    • What model of MSP430 Launchpad are you using? I have difficulty identifying it from the picture.
    • Can you tell us what are the values of DP83TG720 registers 0x0002 and 0x0003?
    • Did you program any registers in the device?

    Best,

    Evan Su

  • 0 in reply to Evan Su
    Prodigy 160 points

    Could you answer my Question? The question is can I change the J10 power to 3.3V since the VDDIO of 720R is 3.3V.

  • 0 in reply to Evan Su
    Prodigy 160 points

    Can anyone support onsite for Continential? the word communication experienced here is too bad

  • 0 in reply to Evan Su
    Prodigy 160 points

    Hello, pls check the result 0x2 and 0x3

  • 0 in reply to Jing Liang
    TI__Mastermind 18950 points

    Hi Jing,

    Apologies that you have felt the communication has been unsatisfactory but we needed more information to understand the situation and provide useful analysis and guidance.

    Jing Liang said:
    The question is can I change the J10 power to 3.3V since the VDDIO of 720R is 3.3V.

    I asked to confirm the board model before I could comment on header J10 because the picture was blurry and different MSP430 models or boards could have different header configuration schemes. If it is the common MSP‑EXP430F5529LP, the User's Guide expects that the MSP430 power rail is typically 3.3 V, which is why the rail is named as 3V3. In my experience I have also always powered the MSP430 using the USB 5V power input --> 3.3 V on-board LDO instead of external power and that would be my normal recommendation. For that particular board model I would be confused at 2.1 V external power because that is not even a common supply or I/O voltage level from what I have worked with.

    Although that MSP430 model can run between 1.8 and 3.6 V, since the I/O voltages of microcontrollers are usually the same as the supply voltage, it is good practice to ensure that microcontroller I/O is at a compatible voltage with the partner device I/O. Otherwise the interface may have data and logic problems.

    Jing Liang said:
    Hello, pls check the result 0x2 and 0x3

    0x2 and 0x3 are read-only device and rev ID registers with known values. The readbacks are not correct compared to what is specified in the datasheet register map and also not stable. This means there is an issue with the communications interface that needs to be debugged and the initial readback for the 0x456h register in your original post is not necessarily the true register value.

    I received an update from the field this morning saying that the issue has been solved, so I assume your team was able to find and resolve the root cause of the incorrect register readback yesterday. You can continue on this thread if there are any remaining problems to debug.

    Best,

    Evan Su

  • 0 in reply to Evan Su
    Prodigy 160 points

    I powered J10 with 3.3V, all data register shows correct now.