C51: Inline Assembly Generates Target Out of Range

Information in this article applies to:

• C51 All Versions

QUESTION

I have added a complex in-line assembly function to my C source file, but I am now getting the following error:

error A51: TARGET OUT OF RANGE

Is this a Compiler problem?

ANSWER

No, it is not a Compiler problem, but an issue of your source code.

You are very likely getting this error on a short JMP instruction (SJMP, JNZ, JZ, CJNE, JC, DJNZ). TARGET OUT OF RANGE indicates that the address specified in the instruction cannot be reached by this instruction.

You may solve this problem with a small change in your source code.

For example, when the following instruction generates the error A51: TARGET OUT OF RANGE:

       JNZ     label

You may re-write this code with:

       JZ      Hlabel
       JMP     label
Hlabel:

MORE INFORMATION

• Refer to ASM in the Cx51 User's Guide.
• Refer to Interfacing C to Assembler in the Cx51 User's Guide.
• Refer to Error A51 in the Ax51 User's Guide.

SEE ALSO

• GENERAL: SRC Directive
• C51: Problems with #pragma ASM
• C51: Getting Inline Assembly to Work
• C51: Comments in Assembly Blocks

Last Reviewed: Thursday, February 25, 2021