Posted on May 17, 2011 at 12:16you can use serial SPI SRAM , but they only go up to 32Kbytes, but they are cheap (30 cents/10K) so you can gang four together, but this is very slow, how fast does it have to be?
or use parallel SRAM using I/O ports to simulate the an external bus (easy to do, speed is much better then serial, but not as fast as internal), using this method you can easily get 128K and much more if needed, but you need a lot of spare ports
Finding 128K SRAM internal is hard, only a few ARM's support that amount of memory and you tend to get alot of junk you don't want and you won't be able to expand, so I don't like that option
