30Oct2016: Nexell EOMA68-S5P6818 Octa-Core Card, Revision 0.1 CAD
From first talking to ZhongweiSemi's CEO (Nexell's partner in China) last week it's been only eight days to getting this PCB design nearly finished. It is based on their K-Project Reference Design which is 70x48mm, where EOMA68 PCBs are 78.1mm by 47.3mm - incredibly similar. A minor compromise has had to be made: the Micro-SD socket has to protrude by around 3mm from the end in order to avoid having to make significant adjustments to the pre-existing DDR3 RAM layout or the pre-existing PMIC layout - both of which are a priority to avoid having to do.
This PCB uses 4 DDR3 x16 RAM ICs, which are only around $USD 2.30 at current prices to achieve 2GBytes of RAM. As was discovered when attempting to do only 2 DDR3 x16 RAM ICs to achieve 2Gbytes of RAM, the 8 gigabit DDR3x16 RAM ICs are a whopping $9 each. By using four x16 ICs the total RAM price can be under $10 instead of a shocking $18. Also, the K-Project Reference Design uses eMMC, which can go up to 32GBytes. This is by a long way going to be a powerful board. Luckily, the S5P6818 is pin-compatible with the 4418, which will allow the possibility of creating an intermediate (quad-core) variant.