I meet a question: I want to make a hardware emulator do to some experiment with mcs-51 microcomputer!But i am not very clear understand the thoery of the emulator! I use a device with 64k FALSH ROM on-chip.it can well connect with the keil debugger!but i don't know where my application code stores! thank you for your help first!
"I want to make a hardware emulator do to some experiment with mcs-51" This is most certainly not a job for a home-brew! An emulator is a device that precisely duplicates the entire behaviour of a processor, plus provides non-intrusive debugging logic for single-stepping, execution trace, examining memory, registers, etc, etc, etc,... This will obviously require an exceptional understanding of every tiniest detail of the internal workings of the 8051. "i don't know where my application code stores" If you need to ask that, then you are certainly not in a position to design your own ICE! If you can't afford an ICE, the next best thing is to get a device with on-chip debug hardware like the Silicon Labs (nee Cygnal) parts: http://www.keil.com/dd/cl/SiliconLabs/8051.htm
I want to make a hardware emulator If you have about 10 man-years for the project, go ahead. Since those of us that have 10 man-years are required to make other products we buy an ICE rather than amking one and thus can not help you. SILabs have, as Andy already mentioned, what I would call a "built in ICE" and if you use these chips, you get almost full ICE for the price of a JTAG cable. Erik