The ARM processor core is a key component of many successful 32-bit embedded systems.
You probably own one yourself and may not even realize it! ARM cores are widely used in
mobile phones, handheld organizers, and a multitude of other everyday portable consumer
devices.
ARM’s designers have come a long way from the first ARM1 prototype in 1985. Over
one billion ARM processors had been shipped worldwide by the end of 2001. The ARM
company bases their success on a simple and powerful original design, which continues
to improve today through constant technical innovation. In fact, the ARM core is not
a single core, but a whole family of designs sharing similar design principles and a common
instruction set.
For example, one of ARM’s most successful cores is the ARM7TDMI. It provides up to
120 Dhrystone MIPS1 and is known for its high code density and low power consumption,
making it ideal for mobile embedded devices.
In this first chapter we discuss how the RISC (reduced instruction set computer) design
philosophy was adapted by ARM to create a flexible embedded processor. We then introduce
an example embedded device and discuss the typical hardware and software technologies
that surround an ARM processor.
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