A peek into the world of
Smartphone
Processors
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Introduction to SoC
There are about 3.1 Billion active smartphone
devices in the world. In the core of every
smartphone, there is a mobile processor
that powers them. The difference between
a CPU (Central Processing Unit) found in a
Personal Computer (PC) and a smartphone’s
processor unit is that unlike in a PC, in mobile
devices, mobile processors aren’t standalone
units. Instead, they are called System-on-a-
Chip (SoC). A SoC is an integrated circuit that
integrates all components of a computer or
other electronic systems.
are low power consumption and the compact
design compared to a desktop processor unit.
These features are there to accommodate
the power and space constraints of mobile
devices.
ARM
From here onwards, this article will mainly
focus on the processing units within these
SoCs. There are two types of concepts
that are available when implementing
the processor hardware. They are RISC
(Reduced Instruction Set Computing) and
CISC (Complex Instruction Set Computing).
The X86 architecture by Intel (which is in
PCs and Apple’s Mac devices) is an example
for CISC. Almost all the smartphone devices
that use ARM CPUs are examples for RISC.
The ARM is a family of RISC architectures for
computer processors. They release updates
to their existing versions periodically. A 'v' in
its name denotes the version. (For example,
ARM version 3 is denoted as ARMv3). From
A SoC is not only limited to a processing ARMv3 to ARMv7, they only supported 32-bit
unit. It can also include a memory, the address space.
Input/output ports, and even secondary
storages too. Sometimes it can also contain In 2011, ARMv8-A architecture added
digital, analog, mixed signals and even radio- support for 64-bit address space and 64-bit
frequency functions. Key features of the SoC arithmetic with their latest 32-bit fixed length
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University of Peradeniya GAUGE Magazine