Yes, the 'T' does mean exactly that.

It's purpoted that the Thumb instruction set is a bit more dense. I've never verified that, but you have to keep in mind that the ARM is a RISC and may have to execute several instructions in place of one 805x instruction. However, the ARM is very fast, at least in some incarnations, and can have as many as three cache levels, hence can keep executing code at a rate far exceeding its memory-bus-performance.

The ARM is a much more advanced architecture than the venerable 805x, but its advanced features of which may not be beneficial to all applications.

There's got to be a good reaosn why there's an ARM in nearly every cellphone, though.

RE