1. A method of operating a processor having one or more registers and running a program comprising a first instruction and a next instruction from a first instruction set, said method comprising: executing said first instruction; in response to said executing, (i) saving the register context of said registers without executing any instructions from said first instruction set; and (ii) removing power from said processor after said saving; returning power to said processor after said removing; after said returning, restoring said saved register context without executing any instructions from said first instruction set; and resuming said running of said program with said next instruction.