ARM OR THUMB CODE

Note: This was originally posted on 5th November 2010 at http://forums.arm.com We all know that there are two kinds of instruction, arm and thumb. Here is the question: how can I get the right instruction...
ARM OR THUMB CODE

Note: This was originally posted on 5th November 2010 at http://forums.arm.com We all know that there are two kinds of instruction, arm and thumb. Here is the question: how can I get the right instruction...
From the CPU's point of view, how does it distinguish an assembly code is an ARM code or a Thumb code?

From the CPU's point of view, how does it distinguish an assembly code is an ARM code or a Thumb code? Is there some signal bit represent the code is ARM or Thumb code, this is just my guess.
From the CPU's point of view, how does it distinguish an assembly code is an ARM code or a Thumb code?

From the CPU's point of view, how does it distinguish an assembly code is an ARM code or a Thumb code? Is there some signal bit represent the code is ARM or Thumb code, this is just my guess.
Does anyone know how I can remotely update code to distant arm system?

I have problem, I have to find a way to update code to my arm device without removing it, for that purpose I'll use serial communication. Does anyone have idea how to do it?