OLIMEX© 2014
A20-OLinuXino-MICRO user's manual
6.2 SD card connectors
There are two SD card connectors on this A20 board. The now common microSD card connector is
located on the top of the board, near the audio in/out connectors.
Note that by default only the micro SD card slot might be used for booting the OS.
However, due to popular demand, there is also an SD/MMC card connector located on the bottom
of the board.
Both SD slots might be used simultaneously – there is no data multiplexing lines. For instance – one
of them might be used for booting the OS, the other – for saving data.
As a general precaution be careful with the SD cards you purchase. There is a big percentage of
fake cards due to the low effort required to counterfeit popular brands and the big demand for SD
cards worldwide. When in doubt – try the same operation with another card from another brand.
Olimex sells microSD cards with Linux or Android images, that have been tested – please refer to
chapter “2.2 Requirements”. Of course, if you already have a large enough microSD card you can
download the official Linux image from the wiki pages:
https://www.olimex.com/wiki/A20-
OLinuXino-MICRO
.
When removing the card, please make sure that you release it from the connector by pushing and
NOT by pulling the card directly (this can damage both the connector and the microSD card).
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
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