• Thumb-2 is the newest version of Thumb.
• It’s present in the Cortex CPU series (or any v7).
• Now a complete architecture: you can have a Thumb-2-only CPU (v7M).
• Mixed 16/32-bit instruction stream provides the economy of space of Thumb combined with most of the speed of pure ARM code.

What does Thumb-2 assembly language look like?

It’s pretty much like ARM assembler. ARM Ltd. have unified the ARM and Thumb assembler formats into UAL – a Unified Assembler Language. New ARM assemblers can take UAL format assembler and output to ARM or Thumb-2.