C51: INITIALIZING AN ABSOLUTELY LOCATED VARIABLE

Information in this article applies to:

• C51 Version 5.50

QUESTION

I have declared a global variable using:

unsigned char xdata foo _at_ 0x2000 = 5;

However, upon compilation I get the following error:

Error 274: 'foo': absolute specifier illegal

How can I initialize an absolutely located variable?

ANSWER

You cannot both specify a location for a variable and initialize it at the same time. The best solution is to initialize the variable seperately in an intitialization routine. For example:

void init_globals(void)
{
  foo = 5;
}

which is then called from the main function.

MORE INFORMATION

• Refer to Absolute Variable Location in the Cx51 User's Guide.

SEE ALSO

• C51: LOCATING INITIALIZED VARIABLES AT ABSOLUTE ADDRESSES
• C51: AVOIDING STARTUP INITIALIZATION OF STATIC VARIABLES
• BL51: INITIALIZING & LOCATING A VARIABLE TO A FIXED ADDRESS

FORUM THREADS

The following Discussion Forum threads may provide information related to this topic.

• How to initialize Absolute variables in code memory?
• How to initial the value when using "_at_" locate instruction?
• I meet the problem : 5623.H(4): error C129: missing ';' before 'data'

Last Reviewed: Friday, July 15, 2005