EQU declarations define names for integer constants. Those names can be used anywhere in the program where a number is expected. It is legal to declare an EQU name whose value is a previously-defined EQU name. For example, it is legal to make the following declarations:

In this example, both A and B are now names for the constant 4.

Note that the names of all EQUs must be valid symbols and the values of all EQUs must be previously-defined EQU names or valid literals in the assembly language syntax.

The value associated with the name must be an unsigned or signed (2's complement) 64-bit integer.

Note that EQU declarations in an assembly language program are always local, which means that the declared names can only be used in the file in which they are declared. Therefore, it is often useful to put the EQU declarations in files that are then included (using .include directives) in all files in which you wish to use the declared names. You can also make global EQU declarations.

If a global EQU declaration and a local EQU declaration both use the same symbol (which is legal), the local EQU declaration has precedence.