Bone A6 uSD Card Schematic Question

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1

On the Beaglebone A6 schematic (and it appears all older version using
the same Molex uSD card connector, at least the A5), P4 pin 11 is
labeled as GND but the net is named SD_CD and appears to act as the SD
card detect. P4 pin 10 is labeled CD, which I assumed was the card
detect pin but is connected to ground.

This is on page 11 in area B4 of the page.

Is the symbol wrong or is the net connected to the wrong pin?
Or am I simply reading the schematic wrong?

The drawing from Molex I've been able to find only appears to list pins
1 through 8, the actual pins that touch the contacts on a uSD card.
The tabs, mostly ground, but also the card detect don't appear to have
pin numbers on them.

Thanks,
Andrew

2

The schematic symbol was not changed when we changed connectors. Wiring and operation is correct. The names on pin 10 and 11 are swapped.

Gerald

3

One more note. Techincally speaking, the microSD specification uses pin 2 as the card detect. While the manufacturers still put this contact on, I saw no harm in connectingi t, but it is inn’t really used, unless someone wants to use it as an interrupt for some reason…

Gerald

4

OK, thanks for the info!
Probably worth it for me to read through the SD physical spec...

-Andrew