5 ms·
> On execution, 16-bit Thumb instructions are transparently decompressed to full 32-bit ARM instructions in real time, without performance loss. That quote is
by RetroSpark 1y ago
> On execution, 16-bit Thumb instructions are transparently decompressed to full 32-bit ARM instructions in real time, without performance loss.
That quote is from the ARM7TDMI manual - the CPU used in the Game Boy Advance, for example. I believe later processors contained entirely separate ARM and Thumb decoders.