344 EMBEDDED SYSTEMS
10.2 | ARM Architecture
With this background, let us get started on the more intricate details of the processor.
10.2.1 | Instruction Set Architecture
It is likely that you have heard the term ‘Instruction Set Architecture’ (ISA) mentioned
in some context or the other. e term implies the user’s i.e. the programmer’s view of
the processor, which constitute the instruction set, addressing modes, registers, etc. ISA
is the assembly programmer’s or compiler designer’s view of the processor. We will base
most of our discussions on ARM7 which was the fi rst and still the most popular of the
ARM processors. Advanced versions may have more enhancements, but the basic archi-
tecture is more or less the same.
10.2.2 | Operating