Both load and store directives are limited to operate on places in
current addressing space. The $$ symbol is always equal to the base address
of current addressing space, and the $ symbol is the address of current
position in that addressing space, therefore these two values define limits
of the area, where load and store can operate.


Combining the load and store directives allows to do things like encoding
some of the already generated code. For example to encode the whole code
generated in current addressing space you can use such block of directives:

Code:

    repeat $-$$
        load a byte from $$+%-1
        store byte a xor c at $$+%-1
    end repeat