ARM VERSION 1.2 - Manual (Page 232)

Thumb Instruction Reference
5-38 Copyright © 2000, 2001 ARM Limited. All rights reserved. ARM DUI 0068B
5.5.2 BKPT
Breakpoint.
Syntax
BKPT immed_8
where:
immed_8 is an expression evaluating to an integer in the range 0-255.
Usage
The BKPT instruction causes the processor to enter Debug mode. Debug tools can use this
to investigate system state when the instruction at a particular address is reached.
immed_8 is ignored by the processor. However, it is present in bits[7:0] of the instruction
opcode. It can be used by a debugger to store additional information about the
breakpoint.
Architectures
This instruction is available in T variants of ARM architecture version 5 and above.
Examples
BKPT 67
BKPT 2_10110