I currently have a 1Mb Parallel SRAM chip in a DIP-32 package. Putting that on a board is causing me all kinds of routing and space headaches. I know that there are nice 8 pin spi or i2c chips that have that capacity, but it seems that they are all eeproms or flash memory. I plan to overwrite data quite frequently and I know that most persistent storage has write limits and (I would assume) slightly slower speeds than vanilla SRAM. If I had an eeprom or something I would be performing a chip erase on each startup, and don't want a part that will wear out too soon. My attempts to find a suitable part on mouser or digikey has turned up nothing, but I am not sure what I am looking for.
Is there any kind of volatile storage that can be accessed quickly over some serial protocol? My MCU is running at 5v supply and logic, but I am willing to shift voltage down if necessary.
Best Answer
The highest standard serial SRAM I have seen available for sale is 256Kb.
1Mb serial is available in FRAM though, here is an example part (from this page)
Note there is a lead time on the 1Mbit parts, but you might possibly be able to grab some samples from Ramtron. They do have the 512Kb part in stock.