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AM3351: Board is not booting from SD-card continuously

mounika meneni
Intellectual 460 points
Part Number: AM3351

We are booting the board with SD card . SD card are divided into two parts boot and rootfs and loaded zimage,MLO,U-boot .

When we are booting from SD-card board is booting after continues on and off board is not booting from Sd card.

We observed  that SD Protect  is high and SD  Detect Pin  is low  even though while booting from Sd Card  

We are using 4GB SD-card and we also tried with another  16 GB SD card then also we observed same Problem  

i am attaching Schematics of SD card below: 

Now , U44 IC present in above Schematics  is removed and  2 & 4 pins and  1 & 3 pins are shorted for SD Detect pins to be low .

We didn't understand why board is not booting from SD card Sometimes.

 

Regards,

Mounika

  • 0
    TI__Guru 62855 points

    The connector you selected does not appear to have a write protect switch. It only has a single normally open switch used for card detect. The card detect switch is connected between pins 9 and 10 of the connector. You should have connected one of these pins to ground and the other pin to the card detect input. You also need a pull-up resistor on the card detect signal that is connected to the same power rail that is powering the IO associated with the card detect input.

    You should not remove U44 from the card detect signal since this would allow ESD events to propagate to the card detect input.

    When designing your PCB, did you perform a timing analysis of the interface?  The analysis must consider the timing requirements of each device along with the output delays of the other device, and you may need to adjust your PCB delays as necessary to provide enough timing margin.

    Did you place a series termination resistor very close to the clock output pin?  If so, what value resistor did you install?

    Regards,
    Paul

  • 0 in reply to peaves
    TI__Guru 62855 points

    I included some additional information and questions in my original post.