[J-core] Which lpddr?

[Rob Landley]

According to wikipedia[citation needed] there are 4 lpddr specs:

  https://en.wikipedia.org/wiki/Mobile_DDR

It looks like we're using lpddr2, because of the 2 gigabit max?
Samsung says it has has 4 gigabit lpddr3 and 8 gigiabit lpddr4:

http://www.businesswire.com/news/home/20130429006782/en/Samsung-Producing-Gigabit-LPDDR3-Mobile-DRAM-20nm-classSamsung

http://global.samsungtomorrow.com/?p=31752

So in theory we're not _that_ far off from being able to do a gigabyte
of ram. Modulo expanding the cache tags and finding chips that are
reasonably priced and don't require our chip to run at 800mhz to talk to
them. :)

Rob