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tusb1310A crystal doesn't work

Other Parts Discussed in Thread: TUSB1310A

As I'm working on build the tusb1310A board but failed check the ULPI clock (about 90MHz) and PIPE3 clock( no working clock ).

All the strap in I set no pull up/down resistor.

I measured some of the strap pins' voltage, 

RX_ELECIDLE=0;

REFCLKSEL1=0;
REFCLKSEL0=0;

Now the crystal is 20Mhz crystal( work normally at other board).

Very strange, after I powered on this 1310A board, I measured a 30M Hz clock at the 24MHz crystal pin( 1310A's XO pin);

Could anyone help about this special abnormal case?

Does the strap pin can be set 0/1 by connect a pull down/up resistor?

Or how can i set the strap pin?

  • Hello Michael,

         We are reviewing your post and we will reply soon.

    regards,

    Diego.

  • Yes,

    The strap pins can be set with a pull-up/down, the TUSB1310A reads the strap pins at the de-assertion of reset.

    Make sure you are following the power-up sequence described on Section 3.1.4 of datasheet.

    Can you share your schematic?

    Regards.

  • Hi, ELIAS:


    The schematic I had sent it to you last day by email!

    I still paste the schematic for more checking

    ;1460.sch_USB3_TUSB1310.pdf

    Another question, after by change crystal mode to clock input mode.

    XI drive by a 30MHz oscillator, the ULPI_CLK checked 60M clock output and 250M pclk looks working.

    And after connected the USB1310A to host, PIN: PWRPRESENT can change to valid(high voltage);

    After this stage, does usb1310A need further configuration drive it to working normally?

  • Can anyone pay attention to this item and help resolved this function?

    Or anyone can sent me a simulation model used in the RTL simulation surrounding?

  • Hello Michael,

    I reviewed your schematic and have some comments:

    Make sure PHY_MODE[] are set according with the datasheet.
    JTAG_TRSTN must be connected to ground.
    AC coupling caps un super speed lines are only required on TX, remove C26 and C27.

    I am not sure what do you mean by "...After this stage, does usb1310A need further configuration drive it to working normally?..."

    Regards.

  • ELIA,

    Thanks for your reply.

    After this stage, does usb1310A need further configuration drive it to working normally?...

    I want to know, if I had done all this:

    PHY_MODE[1:0] :  no pull up/down, keep float;

    JTAG_TRSTN: connected to ground;

    All the strap pins: XTAL_DIS,SSC_DIS,PIPE_16BIT,ISO_START,ULPI_8BIT,REFCLKSEL1,REFCLKSEL0;

    keep float;(I checked the voltage after power on, all these pins' voltage are 0V)

    And the XI,XO connected a 20M crystal as the reference schematic.

    But I measured the XO pin, I checked a 30M clock.

    This looks very strange.

    So I want to know is there any building step need to be modifid?

  • Hello Michael,

    I'm confused, are you using a crystal or an oscillator to drive the TUSB1310A?

    Does it work with the oscillator but not with the crystal? If so, remove R17 and verify that the load capacitors meet the crystal specs.

    You say that the crystal is 20MHz and you are measuring 30MHz at the output, but the schematic show a 30MHz crystal.

    After the TUSB1310A is out of reset and the reference clock is stable and all the strap options has been set properly, then the device is ready to start interfacing with the ULPI and PIPE.

    Regards.