IBM Support

Defining and Referencing Variables and Constants in High Level Assembler Part I

Technote (FAQ)


What are the assembler DC/DS operands, and how do I use them?


HLASM provides assembler directives for defining variables and constants


Assembler programs reference storage areas during program execution. The storage areas may be defined within the scope of the application program code or be located elsewhere in memory. High Level Assembler (HLASM) provides two assembler directives which an assembler application programmer uses to define these storage areas: DC (Define Constant) and DS (Define Storage). The key difference being DC will initialize the storage area, DS will not.

The attached pdf explains some of the details of these two instructions and shows examples of using them.

Document information

More support for: High Level Assembler and Toolkit Feature

Software version: 1.6

Operating system(s): z/OS, z/VM, z/VSE

Software edition: Enterprise

Reference #: 1598281

Modified date: 2015-12-14