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!
Xu, It's required for 3 memory segments for your Mon51 application. One for 4~5Kbytes as mon51 code memory(ROM). One banked (or not ) Von.Nuemam linked ram for your application code. One for your application data. When reset, mon51 takes control on your board. PC is pointed to mon51 code memory, the Von.Nuemam memory act as data memory at this time. Mon51 communicates with keil and download your application code into that memory area. the variables for mon51 is also stored in this area. Mon51 write with 'WR' and read with'RD'. Your application data area is out of the Mon51 control. When you start up your application program, your own code takes control on your board. It simply runs as started from reset and do not "know" Mon51 runs previously. Now the application data area is available for your code. The Von.Nuemam area is sampled by PSEN as program code. So you must connect RD & PSEN with a AND gate together, to RD on Von.Nuemam ram. Relocate your interrupt segment and code, xdata segment when you linked up your application program.