1. A method for invasive debug of a processor without processor execution of instructions, comprising: using a debug port of said processor, accessing a memory mapped I/O of said processor; using said memory mapped I/O, initiating an operation that causes said debug port to gain access to registers of said processor; and from said debug port, and based on said access to said registers of said processor, executing said invasive debug of said processor, without said processor executing similar debug instructions.