I've been trying to find certain information about JTAG but have not been very successful.
For my own edification I'd like to learn how JTAG can be used to load a program into memory and executed. Then I'd like to be able to store a program into flash memory. I'm considering a Sharp LH7A400 based on the ARM922T core.
I'd like to use a PC running Linux as the host on which I will cross-compile my programs and download them onto the target via a JTAG interface. I have found some information on JTAG-tools and JTAG-ARM9. I can examine each of these programs to see what they do, but I won't know why they do it.
I'd like to learn the theory of operation of JTAG that would allow me to achieve the goal stated above. In particular I'm interested in: the communication protocol (commands, etc.), signals required and the timing of the signals, and cable specification (pinouts, connectors, shielded twisted pair or whatever), plus whatever else you feel is appropiate. Is anyone aware of a tutorial or other information I can access that might help me?
Has anyone added the definition of a new processor to JTAG-tools? If so, is it a matter of specifying the appropriate files, or is something more involved? Is the process documented, or could you describe what changes you made?
Is this an appropriate place to post this message? If not, can you suggest a better place.
Thanks, Randy Cooper