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Error: UNRESOLVED EXTERNAL SYMBOL and REFERENCE MADE TO UNRESOLVED EXTERNAL

Hello everyone,

I am using Keil uVision2 to write my assembler code. I am always getting the same error. I searhed on Google and everbody says the solution is in the Keil manual but I could not find anything. To make it clear, I would want to say what I did so far.

1. Created a project,
2. Selected Atmel T89C51CC01,
3. Clicked new button and wrote my assembler code,
4. I added .asm code in the project.
5. Compile it and get the warnings.

Here is .plg file:

Build target 'Target 1'
assembling STARTUP.A51...
assembling defa.asm...
linking...

*** WARNING L1: UNRESOLVED EXTERNAL SYMBOL
    SYMBOL:  ?C_START
    MODULE:  STARTUP.obj (?C_STARTUP)
*** WARNING L2: REFERENCE MADE TO UNRESOLVED EXTERNAL
    SYMBOL:  ?C_START
    MODULE:  STARTUP.obj (?C_STARTUP)
    ADDRESS: 000DH
Program Size: data=9.0 xdata=0 code=4131
creating hex file from "my"...
"my" - 0 Error(s), 2 Warning(s).

Parents
  • In this example, I tried to send my .hex file to the microcontroller. In order to correct it, I read data from microcontroller and normally I was supposed to see longer sentences because mov 18h, #01001010b would be converted 20 18 4A. Here, 20 is mov, 18 is 18 and 4A is #01001010b. There were 4 lines in my code but when I read from microcontroller I saw just 02 00 10. I supposed something like that,

    20 18 4A 20 20 24 20 28 52 20 30 7F 20 38 36 ...

Reply
  • In this example, I tried to send my .hex file to the microcontroller. In order to correct it, I read data from microcontroller and normally I was supposed to see longer sentences because mov 18h, #01001010b would be converted 20 18 4A. Here, 20 is mov, 18 is 18 and 4A is #01001010b. There were 4 lines in my code but when I read from microcontroller I saw just 02 00 10. I supposed something like that,

    20 18 4A 20 20 24 20 28 52 20 30 7F 20 38 36 ...

Children