These are numeric constants. In A32 and T32 code they are
integers in the range 0 to 232-1. In A64
code, they are integers in the range 0 to 264-1.
They address the memory directly. You can use labels to represent
absolute addresses using the
EQU directive. You can
specify the absolute address as A32, T32, or data to ensure that
the labels are used correctly when referenced in code.