cembeddedmicrocontrollerkeil

How to change memory mapping start address at Keil with 8051 processor

env

detail

When I downloaded the program to the board, it didn't work. I reviewed the memory mapping tables.

I found the startup address was 0x800, but the memory mapping is 0x000~0x7ff.

So I changed the linker control string from:

PRINT(".\asd.m51") RAMSIZE(256)

I changed RAMSIZE(256) to RAMSIZE(128) and add memory limiting string 'CODE(0X0000-0X07FF)':

PRINT(".\asd.m51") RAMSIZE(128) CODE(0X0000-0X07FF)

But it still maps to address over 0x800 and returns this error:

*** ERROR L107: ADDRESS SPACE OVERFLOW

I also change other settings:

enter image description here

What should I do?

data_sheet

Solution

  • Apparently you are using the evaluation version of the development kit.

    The relevant page "Limitations" lists (among others) this restriction:

    C51 Evaluation Tools

    • Programs start at offset 0x0800. Programs generated with the evaluation software may not be programmed into single-chip devices with less than 2 Kbytes of on-chip ROM.

    There is no way around it. So you need to buy a license and install it, if you urgently want to use Keil C51.

    Or you use another compiler (and editor/IDE). Unfortunately (for you) recommendations are off-topic here, but if you use your web fu with "open source c compiler for 8051", I'm sure you will find some suitable compiler system.