NOTE

Assembler Directives and Pseudo-Operations

.BLOCK and .BLOCKZ Pseudo-Operations

.BLOCK and .BLOCKZ Pseudo-Operations

The .BLOCK and .BLOCKZ pseudo-operations reserve a block of storage.

Syntax

.BLOCK [ num_bytes]

.BLOCKZ [ num_bytes]

Parameters

num_bytes An integer value for the number of bytes you want to reserve. Permissible values range from zero to 0x3FFFFFFF. The default value is zero.

Discussion

The .BLOCK pseudo-operation reserves a data storage area but does not perform any initialization. The .BLOCKZ pseudo-operation reserves a block of storage and initializes it to zero.

When you label a.BLOCK pseudo-operation, the label refers to the first byte of the storage area.

For large blocks, it is usually better to use the .COMM directive to allocate uninitialized space. Since .COMM storage is allocated at run time, it doesn't increase the size of the object file.

Under the present implementation of the Assembler, the .BLOCK pseudo-operation also initializes the reserved area to zero.

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Chapter 4