ARM VERSION 1.2 - Manual (Page 214)

Thumb Instruction Reference
5-20 Copyright © 2000, 2001 ARM Limited. All rights reserved. ARM DUI 0068B
5.2.4 ADD, pc or sp relative
Add an immediate constant to the value from sp or pc, and place the result into a low
register.
Syntax
ADD Rd, Rp, #expr
where:
Rd is the destination register. Rd must be in the range r0 - r7 .
Rp is either sp or pc .
expr is an expression that evaluates (at assembly time) to a multiple of 4 in the
range 0-1020.
Usage
This instruction adds the value of expr to the value from Rp , and places the result in Rd .
Note
If Rp is the pc, the value used is:
(the address of the current instruction + 4) AND &FFFFFFFC .
Condition flags
This instruction does not affect the flags.
Architectures
This instruction is available in all T variants of the ARM architecture.
Examples
ADD r6,sp,#64
ADD r2,pc,#980
ADD r0,pc,#lit-{PC} ; lit - {PC} must evaluate, at assembly
; time, to a multiple of 4 in the range
; 0 to 1020