Global Standards for the Microelectronics Industry
card detect [CD(n)]
The two signals, CD1 and CD2, that provide for proper memory card insertion detection and are positioned at opposite ends of the connector to facilitate the detection process. The signals are connected to ground internally on the memory card; thus they will be forced low whenever a card is placed in a host socket. The host socket interface circuitry shall provide 10-kΩ pull-up resistors to VCC on each of these signal pins.
References:
JESD21-C, 1/97