Content originally posted in LPCWare by lpcxpresso-support on Fri May 30 01:09:58 MST 2014
Erase by page will loop through erasing every page in your flash device.
Mass erase will use the Flash's "erase device" function (if it exists). If the device does not support Mass erase, then Erase by page will be performed instead.
Mass erase is generally quicker.