SD Card CD pin confusion

[leejersoon]

Hi everyone. I am not clear of this pin. I know that the SD Card CD pin will be low once it is inserted. But I saw that on the SD Card there is 1 CD pin, and on the SD Card Holder there is another CD pin.

1. Are they connected together if I insert the SD Card into the holder? If not which one has a higher priority?
2. If the CD pin is low when inserted, but if I pull the CD pin high, will the SD Card be detected as missing or can't read/write?

 

[FvM]

I guess you are confusing SDcard CD/DAT3 pin and card detection switch of card connectors. The latter has no connection to the card. CD/DAT3 is acting as chip select in SPI mode and can't work for card detect purposes.