Reference Guide

60 Chapter 4
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.
NOTE Under the present implementation of the Assembler, the .BLOCK
pseudo-operation also initializes the reserved area to zero.