OLIMEX© 2015
A20-OLinuXino-MICRO user's manual
6.2.1 SD/MMC1 slot
The schematic related to the SD/MMC1 (microSD connector) is shown below:
SD/MMC1 slot is the “smaller” microSD card slot, located on the top of the board.
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.
microSD card 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
-
4
VDD
-
5
CLK/SCLK
SD0-CLK(L20)
6
VSS2
-
7
DAT0/DO
SD0-D0(M19)
8
DAT1/RES
SD0-D1(M20)
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