21.15 DCB

The DCB directive allocates one or more bytes of memory, and defines the initial runtime contents of the memory.


{label} DCB expr{,expr}...



is either:

  • A numeric expression that evaluates to an integer in the range –128 to 255.

  • A quoted string. The characters of the string are loaded into consecutive bytes of store.


If DCB is followed by an instruction, use an ALIGN directive to ensure that the instruction is aligned.

= is a synonym for DCB.


Unlike C strings, ARM assembler strings are not nul-terminated. You can construct a nul-terminated C string using DCB as follows:

C_string   DCB  "C_string",0
Non-ConfidentialPDF file icon PDF versionARM 100069_0608_00_en
Copyright © 2014–2017 ARM Limited or its affiliates. All rights reserved.