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!
"It's my understanding that the majority of chips that include a JTAG interface also include the on-chip debug functionality, though. Is that generally the case?" I think so. But, as you obviously know, it ain't necessarily so...! Some chips have JTAG but no on-chip debug (eg, the uPSDs mentioned earlier); some chips have on-chip debug, but no JTAG (they use some other proprietary interface).
I guess that you are designing an 8051 device. You may use either the ISD51 or FlashMonitor within your device. Another way is that you build a debugger peripheral on silicon and then use the AGDI interface(http://www.keil.com/appnotes/docs/apnt_145.asp) to connect it with the uVision Debugger.