6.3.13. COMMON

The COMMON directive allocates a block of memory, of the defined size, at the specified symbol. You specify how the memory is aligned. If alignment is omitted, the default alignment is 4. If size is omitted, the default size is 0.

You can access this memory as you would any other memory, but no space is allocated in object files.

Syntax

COMMON symbol{,size{,alignment}}

where:

symbol

is the symbol name. The symbol name is case-sensitive.

size

is the number of bytes to reserve.

alignment

is the alignment.

Usage

The linker allocates the required space as zero initialized memory during the link stage.

Example

        COMMON    xyz,255,4   ; defines 255 bytes of ZI store, word-aligned
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