OLIMEX© 2017
A20-OLinuXino-LIME2 user's manual
schematic shown below:
This slot is typically used for booting the OS, due to the larger capacities of the microSD cards (compared
to SD or MMC cards). It is suggested to have an SD card with a proper Linux/Android image especially if
you have ordered a version of the board without NAND memory. It is also recommended to use Class 10
(10MByte/sec) card for faster read/write operations, lower class cards (especially higher capacity ones)
might slow down the whole system.
SD/MMC connector
Pin # Connector signal name
Wire name (processor pin)
1 DAT2/RES
SD0-D2 (K19)
2 CD/DAT3/CS
SD0-D3 (K20)
3 CMD/DI
SD0-CMD (L19)
4 VDD
-POWER CIRCUIT-
5 CLK/SCLK
SD0-CLK(L20)
6 VSS2
-POWER CIRCUIT-
7 DAT0/DO
SD0-D0(M19)
8 DAT1/RES
SD0-D1(M20)
Additionally, there are the WP and CP switches that are responsible, respectively, for sensing whether the
card is locked for reading and whether there is a card inserted.
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