Talk:Embedded Systems/ARM Microprocessors

I cut this paragraph from the article:


 * The ARM processor is a 32-bit RISC design. (Recent cores can dynamically switch between their 32-bit instruction set and an alternative 16-bit instruction set, which enables higher code density and therefore lower cost memory).

The Thumb instruction set is a "32-bit design" (even though it uses 16 bit instructions), in the same way that the Microchip PIC 16F877 is a "8 bit design", even though it uses 14 bit instructions.

So Thumb mode has higher "code density" than native ARM mode? I *suspect* that is true, but has anyone actually measured it? And how does that measured code density compare to the code density of, say, the Freescale 68k or the Freescale PowerPC or the Freescale the Atmel AVR or the Microchip dsPIC ? (Or, for that matter, using direct-threaded Forth or Jazelle or  p-code on top of native ARM code ?) --DavidCary 01:14, 23 February 2007 (UTC)