Analog Devices ADSP-BF506F Hardware Reference Manual page 984

Functional Description
Sockets supporting this feature can have the card detect pin de-bounced
and connected to a GPIO pin in order to allow not only interrupt-driven
card detection but also interrupt-driven card removal. This is the most
reliable and efficient method of detecting the insertion and removal of a
card as some MMC devices may not implement the card detect pull-up
resistor on the
can have the interrupt level inverted to then generate an interrupt on card
removal.
The final approach to detecting the insertion and removal of a card is to
simply use software polling. Software would poll the slot periodically
using the card identification commands for the supported card types.
Once a card is inserted, this will result in valid responses being sent back
to the host; when the card is removed, command and data timeout errors
will be observed.
21-12
signal. Once a card is detected, the GPIO pin
RSI_DATA3
ADSP-BF50x Blackfin Processor Hardware Reference