SPRAD21E May 2023 – February 2024 AM620-Q1 , AM623 , AM625 , AM625-Q1 , AM625SIP , AM62A3 , AM62A3-Q1 , AM62A7 , AM62A7-Q1 , AM62P , AM62P-Q1
It is recommended to provision for a software enabled (controlled) power switch (load switch) that sources the SD Card power supply (VDD). A fixed 3.3 V supply (IO supply connected to the processor) is connected as an input to the power switch.
Use of power switch allows power cycling of the SD Card (since this is the only way to reset the SD Card) and resetting the SD Card back into its default state.
It is recommended to implement the SD Card power switch enable reset logic using a three input AND gate. One of the AND gate input is connected to the processor general purpose input/output (GPIO) pin. The AND gate input has provision for pullup and 0 Ω to isolate the GPIO for testing or debug. The other two AND gate inputs are connected to the Main Domain POR (cold reset) status output (PORz_OUT) and Main Domain warm reset status output (RESETSTATz) Signals.
If SD Card is configured as a boot device ensure that the external power switch sourcing the SD Card power supply defaults to ON (powered state).
For the implementation details, see the device-specific SK.