• State Resolved
  • Locked Locked
  • Replies 1 reply
  • Subscribers 98 subscribers
  • Views 8574 views
  • Users 0 members are here
Support feedback
Options
Options
Related

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.

How to connect the SD card data3 as a card detection

Ray Chi
Prodigy 30 points
Other Parts Discussed in Thread: AM3352

We are working on a AM3352 based custom board with Micro SD card connector without a separate card-detect pin connected to GPIO of host processor(as in Craneboard).

According to SD card spec, DAT3 pin can be used for card detection purpose. 

How to connect this pin?

  • 0
    TI__Guru**** 393215 points
    Hi Ray,
     
    The DAT3/CD card detection mechanism involves an internal pull-up resistor inside the SD card, which can be controlled by ACMD42 (SET_CLR_CARD_DETECT). However the specification says that this is not a preferred mechanism for card detection. Moreover it won't work with MMC cards. And last, this won't work with external pull-up resistors on the card interface. The preferred card detection mechanism is a mechanical switch on the card connector.