• State
  • Locked Locked
  • Replies 4 replies
  • Subscribers 78 subscribers
  • Views 165 views
  • Users 0 members are here
Support feedback
Options
Options
Similar topics

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

Original question:

MSP-EXP430F5529LP: Regarding designing of MSP-EXP430F5529LP

MSP-EXP430F5529LP: Related to USB port of MSP430F5529LP controller

Shubham Yadav
Intellectual 285 points
Part Number: MSP-EXP430F5529LP

Tool/software:

Dear Sir,

We have designed our custom PCB using an MSP430F controller, in which we are using its USB interface. I have attached the schematic for your reference; please have a look into it. We have designed 5 custom PCBs, in which 4 we are able to detect its USB interface showing in the HID interface of the device manager. Actually, we are facing the problem in the 5th one; we are not able to detect the USB port of the MSP controller. I have verified all connections and components, and all are correct. There are a few observations that I want to share with you.

In the working board where my MSP USB port is working properly, without pressing the BSL switch, still voltage has been observed at the PUR pin, which is 3.06V, and after pressing the BSL, the voltage has come down to 3.02V. Whereas in the board where we are not able to detect the USB port of MSP in that board before pressing the USB BSL switch, voltage observed at PUR pin 0.00v and after pressing the switch, it is 2.96. I am not getting any clue why this is happening, as all connections are proper. Does the IC we received be damaged? Please help me out. Also, does the PUR remain always high internally? what is the function of it? Does is there any point where we have to check?

5857.Sheet1 (1).pdf

Waiting for your response,
Thanks & Regards,
Shubham

  • 0
    TI__Expert 3365 points

    Hi Shubham, thanks for the question. I suspect if you have an identical setup but only one board is malfunctioning, you may have an issue with the device itself. Can you look at the register map on the defective device and find the USBCNF register to read bits 1 and 2? For this particular pin, it can be enabled in a high impedance state or driven high (represented by the status of bit 2 in the aforementioned register). so If you are getting an unexpected value on the PUR pin, this could be caused by the PUR pin EN being 0b. Its not clear to me why only this device would be having this issue though, so I still think the MSP may have somehow suffered some damage.

    -Brian

  • 0 in reply to Brian Dempsey
    Intellectual 285 points

    Dear Sir,

    Actually, we are using MSP internal bootloader for communication; we haven't flashed any our firmware. There are few doubts which I have and also there are some observations which I want to share with you:

    Doubts:

    1) Does the PUR pin has internal PULL-UP? If yes, what is the pull-up value, as it has been shown as "1" in the attached diagram?
    2) Is there any possibility of the internal bootloader getting corrupted? If yes, then how can I flash the new bootloader in to my MSP430 chip? From where I can get the bootloader?

    Observations:

    Sir, in one of my working boards, the voltage coming at the reset pin of the MSP430F is 3v3 as it is pulled up so that voltage should only come. Where as in non-working board the voltage coming at the reset pin is 0.5v, I am not getting clue how 2.5v is getting dropped. So, whether this is causing issue?

    As I have already shared the MSP430 schematic section of my board, please have a look into it...
    Waiting for your response,

    Thanks & Regards,
    Shubham Yadav

  • 0 in reply to Shubham Yadav
    TI__Expert 3365 points

    Hi Shubham, please find my comments below respective to your questions:

    1) if a full-speed USB device is attached to a USB host, the MSP430 USB module has a software-controlled pin that activates a pullup resistor. The bit that controls this function is PUR_EN as in your diagram above. If software control is not desired, the pullup can be connected directly to VUSB, so this should translate to 3.3V based on this diagram in the TRM.

    2) Its hard to tell what the issue could be on this with a custom board, can you verify the MSP chip is correctly oriented on the board? The bootloader will not be corrupted as it is something that remains the same in the ROM, burned into the metal layer itself.

  • 0 in reply to Brian Dempsey
    TI__Expert 3365 points

    Also, can you verify that you are able to at least program the board that has the issue?

**Attention** This is a public forum