Dear Erik,

I hope you can understand my problem 1st before you say give up... I need your help and hope you can help me....

Now i'm using Von Neumann architecture for my external ram. A single block of memory may mapped to act as both data and program memory.

Now, c52 able to run my data and program using SRAM very good but c52 pin EA must switch to GND but the app.c must start at 0x0000 and Interrupt vector also must set to 0x0000. If the app.c Start-up and Interrupt vector both referred to 0x2000 or 0x8000 then it will no work already and i would like to try to running my program without switch the EA-to-GND which mean after i downloaded the app.hex to SRAM then jump to 0x2000 or 0x8000 address then my c52 will run my application code at SRAM already.

Is it possible to do that?

Another case is interrupt (eg Serial-Interrupt, Interrupt service routine.) problem...

Please guide me how to do...

Thank you very much,
Tang