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Const address in bank not "linked" by LX51

Gautam R

I am trying to locate const in a file into a particular bank and access it in the same bank but from a different file. From the map file const is located correctly at the specified address in the bank. However the compiled code to access this const references an address 0 instead of the const address.

Here is a simple banking application...

datafile.c contains

unsigned char const code  message0[] = {'a','b','c','\n'};

C_MESS0.c contains

extern unsigned char const code  message0[];
unsigned char const code  message7[] = {'d','e','f','\n'};

void mess0func()
{
 char x;
 x = message0[0];
 printf("%c", x);

 x = message7[0];
 printf("%c", x);
}

Both files are configured for bank 0 in the IDE. Code banking is selected with two banks and starting address 0x8000. User segment in the IDE is set to ?CO?datafile(B0:0x8000), ?CO?C_MESS0(B0:0x82f0).

The map file contains

      00808004H   CODE/B0  ---       mess0func
      00808000H   CONST/B0 ---       message0
      008082F3H   CODE/B0  ---       message7

When I see the .cod file generated by the linker...

   21:  x = message0[0];
B0:008004 900000            MOV     DPTR,#message0
B0:008007 E4                CLR     A
B0:008008 93                MOVC    A,@A+DPTR
B0:008009 F508              MOV     x,A
   22:  printf("%c", x);
B0:00800B 7BFF              MOV     R3,#0FFH
B0:00800D 7A82              MOV     R2,#HIGH 010082F0H
B0:00800F 79F0              MOV     R1,#LOW 010082F0H
B0:008011 85080C            MOV     ?_printf?BYTE+03H,x
B0:008014 1200A3            LCALL   _printf
   23:  x = message7[0];
B0:008017 9082F3            MOV     DPTR,#message7
B0:00801A E4                CLR     A
B0:00801B 93                MOVC    A,@A+DPTR
B0:00801C F508              MOV     x,A
   24:  printf("%c", x);

Notice that the first assembly line is 900000 instead of 908000

It appears that const is processed correctly in the same file but not in a different file.

I can't figure out what I am missing?

Build parameters:
C51 control string: OBJECTADVANCED OPTIMIZE (6,SPEED) BROWSE DEBUG CODE SYMBOLS
AX51 : GENONLY SET (SMALL) DEBUG XREF EP
LX51: TO "BANK_EX2" BankArea (0x008000, 0x0082FF) CODE IXREF SEGMENTS ( ?CO?datafile(B0:0x8000), ?CO?C_MESS0(B0:0x82f0) )

Here are the tools used..

IDE-Version:
µVision3 V3.72
Copyright (c) Keil Elektronik GmbH / Keil Software, Inc. 1995 - 2008

Tool Version Numbers:
Toolchain: PK51 Prof. Developers Kit Version: 8.06
Toolchain Path: C:\Keil\C51\BIN\
C Compiler: C51.Exe V8.06
Assembler: AX51.Exe V3.02
Linker/Locator: LX51.Exe V4.10a
Librarian: LIBX51.Exe V4.24
Hex Converter: OHX51.Exe V1.36b
CPU DLL: S8051.DLL V3.64
Dialog DLL: DP51.DLL V2.48f
Target DLL: BIN\MON51.DLL V2.41
Dialog DLL: TP51.DLL V2.48f

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