Solution to interface SD card with microcontroller using only 2 pins (I2C/SPI)
Driving an SD CARD with 2 pins is not possible.
Driving an SD CARD with 3 pins might be doable in 1-bit mode:
Pin 1  -&gt;  CMD
Pin 2  -&gt;  CLK
Pin 3  -&gt;  DAT_0

Take a look here for more detailed info in 1-bit mode:
https://www.keil.com/pack/doc/CMSIS/Driver/html/group__mci__interface__gr.html
As far as I know 2-bit mode doesn't exist.