OLIMEX© 2017
A20-OLinuXino-LIME2 user's manual
6.12 Additional hardware components
The components below are mounted on OLinuXino but are not discussed above. They are listed here for
completeness:
Reset button –
used to reset the board
Power button –
used to reset the board
Recovery button –
used to reset the board
1GB = 2×[4Gb(256M x 16b)] DDR3 SDRAM –
the exact memory used currently in the board is
SAMSUNG K4B4G1646D-BCK0
In the latest Debian images the DDR3 RAM memory is set at 384MHz, which is the most conservative
and stable clock for the A20 designs. This is the recommended clock for boards in heavy duty designs.
The lower the RAM clock – the greater the stability. We recommend performing stability tests in a real
environment and decide what value is the most stable in your specific case. The value that we use in our
default images is 384 just in case somebody uses the board in environments with higher than typical
ambient temperature or in applications that stress the memories all the time.
If you wish to change the clock of the RAM memory you need to rebuild the u-boot as per our
instructions and either set higher clock speed in the MENUCONFIG or directly change the value of the
“CONFIG_DRAM_CLK” in the defconfig file for the board.
The DDR3 memory part name in the schematic might be outdated. We have used a number of different
but fully compatible DDR3 memories due to supply unavailability. It is always recommended to check
the exact memory name printed on the component itself.
4GB =1×[32Gb(4096M x 8b)] NAND FLASH
– only available on the 4GB version of the board; the
exact memory used in the board revision mentioned is HYNIX H27UBG8T2BTR
PWR_LED – turns on upon powering the board
CHGLED – lights when charging a battery connected to the Li-Po battery connector.
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