ASM51

Step 1: Assign the variable into a named section in source code:

#pragma udata big_scn
char big_array[0x180];
#pragma udata

Step 2: Create the larger region in the linker script:
Before:

DATABANK NAME=gpr3 START=0x300 END=0x3FF
DATABANK NAME=gpr4 START=0x400 END=0x4FF


After:

DATABANK NAME=big_scn START=0x300 END=0x47F PROTECTED
DATABANK NAME=gpr4 START=0x480 END=0x4FF
SECTION NAME=big_scn RAM=big_scn

Step 3: Reference only through a pointer:

char *big_array_ptr = &big_array[0];
big_array_ptr[0x100] = 5;
while( big_array_ptr[x] != 20 )