1. An Introduction to System on Chip based
Smartphone Processors , working , and
their Architecture.
SoC Based SmartPhone Processors
Ankush Kumar
Electronics And
Communication
2. Contents
Introduction to Soc
SoC vs. CPU
SoC Based Android Processors
Architecture of Processors
SoC vs. CPU
The World Of ARM
GPU
Understanding “Clock Speed” , And “Cores”
Multi – Threading and HyperThreading
References
3. What is a SoC?
A system on a
chip or system on
chip (SoC or SOC) is
an integrated circuit (IC) that
integrates all components of
a computer or
other electronic system into
a single chip. It may
contain digital, analog, mixe
d-signal, and often radio-
frequency functions—all on
a single chip substrate.
-From
Wikipedia
4. Structure of SoC
A microcontroller, microprocessor or digital signal
processor (DSP) core – multiprocessor SoCs
(MPSoC) having more than one processor core
Memory blocks including a selection
of ROM, RAM, EEPROM and flash memory
Timing sources including oscillators and phase-
locked loops
Peripherals including counter-timers, real-
time timers and power-on reset generators
External interfaces, including industry standards such
as USB , Ethernet, USART, SPI
Analog interfaces including ADCs and DACs
Voltage regulators and power management circuits
6. SoC CPU
Advantage of an SoC is its size: An SoC is only a little
bit larger than a CPU, and yet it contains a lot more
functionality. If you use a CPU, it’s very hard to make a
computer that’s smaller than 10cm (4 inches) squared,
purely because of the number of individual chips that you
need to squeeze in. Using SoCs, we can put complete
computers in smartphones and tablets, and still have
plenty of space for batteries.
Due to its very high level of integration and much
shorter wiring, an SoC also uses considerably less
power — again, this is a big bonus when it comes to
mobile computing. Cutting down on the number of
physical chips means that it’s much cheaper to build a
computer using an SoC.
7. The only real disadvantage of an SoC is a complete
lack of flexibility. With your PC, you can put in a new
CPU, GPU, or RAM at any time — you cannot do the
same for your smartphone.
Ultimately, SoCs are the next step after CPUs.
Eventually, SoCs will almost completely consume
CPUs. We are already seeing this with AMD’s Llano
and Intel’s Ivy Bridge CPUs, which integrate a
memory controller, PCI Express, and a graphics
processor onto the same chip.
SoC CPU
8. Why do we use Soc In
Smartphone Processors?
Smart phones are smaller computers, they
require almost the same components we see
in laptops in order to offer us Apps, music and
video playing, 3D gaming support, advanced
wireless features, etc
Smartphones do not offer the same amount of
internal space as laptops for the various
components needed such as the logic board, the
processor, the RAM, the graphics card, etc
Thanks to the wonders of miniaturization, SoC
manufacturers, like Qualcomm, Nvidia or Texas
Instruments, can place some of those
components on a single chip, the System on a
Chip
9. What’s Inside A SmartPhone
Processor
A. CPU – Single- or multiple-core, this is what makes everything possible on
your Smartphone. Most of them Based on ARM technology.
B. Memory – SoCs come with various memory architectures on board
C. GPU – Responsible for handling those complex 3D games on the
Smartphone or tablets.
D. Northbridge – this is a component that handles communications between
the CPU and other components of the SoC including the southbridge
E. Southbridge – a second chipset usually found on computers that handles
various I/O functions. In some cases the southbridge can be found on the
SoC
F. Cellular radios – some SoCs also come with certain modems on board that
are needed by mobile operators.
G. Other radios – Responsible for other types of connectivity, including Wi-Fi,
GPS/GLONASS or Bluetooth.
H. Other circuitry
11. Understanding the world of ARM
“ARM Holdings plc is the British-based company that,
since 1983, has developed the ARM microprocessor
instruction architecture which is used inside their ARM
processor cores.”
ARM has dominated the mobile space for many years,
largely thanks to the lower power consumption of its
processors (and improved battery life) when compared to
the opposition. Intel has been attempting to make inroads
into the markets in recent years with the x86 that is popular
on the desktop, but with limited success.
CPUs are based on ARM architecture.
This is created by ARM Holdings and includes an
instruction set that controls how the CPU works.
This is licensed to the various SoC manufacturers who
incorporate it into their products.
12. WHAT IS AN INSTRUCTION SET ?
An instruction set, or instruction set
architecture (ISA), is the part of the computer
architecture related to programming, including the
native data types,
instructions, registers, addressing modes, memory
architecture, interrupt and exception handling, and
external I/O. An ISA includes a specification of the set
of opcodes (machine language), and the native
commands implemented by a particular processor.
An instruction set is the interface between a
computer's software and its hardware, and thereby
enables the independent development of these two
computing realms.
13. ARM operates quite differently from Intel . Intel designs and
builds all of its own processors, ARM instead creates
instruction sets — any CPU following them will be able to run
ARM-compatible code. It also creates reference designs for
processors that fit their instruction sets, which allows
companies to easily produce their own chipsets around ARM’s
core designs.
Some companies, like Nvidia, Samsung, and Texas
Instruments simply license and adopt the ARM CPU
reference design, whereas others, like Qualcomm and
Marvell, license only the instruction set and create their
own processors to fit them.
ARM’s most recent instruction set is version 7, and the first
ARMv7 reference design was Cortex A8, whose architecture
is found in today’s high-end Smartphone.
14. WHY DO WE PREFER SNAPDRAGON ?
Qualcomm don’t actually use the reference ARM
processor core designs. Instead they take cues from the
ARM Cortex-A8 and make improvements that they
package into their very own Scorpion and Krait CPUs.
This obviously requires more research and development ,
but is apparently slightly better for media-related
operations and power efficiency compared to the
standard Cortex-A8.
15. A chip block diagram for the Snapdragon S4 SoCs
using Krait CPUs
16. Understanding GPU
The GPU is used entirely for all 3D rendering in
games and applications. The Cortex processing
cores are simply not designed to handle these sorts
of tasks and in all operating systems the GPU will
take over from the CPU to handle the rendering
more efficiently. The CPU will help out for certain
calculations while rendering 3D models on screen
(especially for games), but the main grunt will be
done by the graphics chip.
18. Cores and ClockSpeed
If computing is a car then the CPU is the engine. The
higher the clock speed, the faster the car (system)
will go. Clock speed is measured in GHz (gigahertz),
a higher number means a faster clock speed . To run
your apps, your CPU must continually
complete calculations, if you have a higher clock
speed, you can compute these calculations quicker
and applications will run faster and smoother as a
result of this.
A core is a single processing unit, multi core
processors have multiple processing units. So a dual
core 3.0GHz processor has 2 processing units each
with a clock speed of 3.0GHz. A 6 core 3.0GHz
processor has 6 processing units each with a clock
speed of 3.0GHz.
19. MultiThreading vs. Hyperthreading
Multi-threading is the
ability of an application or
operating system to
utilize multiple cores for
processing. When apps
are written with multi-
threading in mind they
can benefit from the
plethora of cores
available in modern
CPUs and see huge
performance increases
over using a single core
Hyper-threading is a
proprietary Intel
technology that allows
a single core to split
into a virtual and a
logical core and share
workload between
the two. Hyper-
threading is especially
useful when apps are
well optimised for
multi-threading.
20. Intel as A Smartphone Processor
ASUS was The First
Smartphone Brand In
INDIA to use Intel
processors and
Hyper Threading
Technology.
Intel has just announced ducking out of the mobile
processor market.
Intel is working on ultra-high end Core m5 and m7
processors, which are designed for the high performance
tablet and lower end notebook market. The company claims
that its latest Core m processors offer 40 percent boosts to
graphics and CPU performance and will be targeting at 2-in-
1 convertible devices and notebooks.
Eeprom - a read-only memory whose contents can be erased and reprogrammed using a pulsed voltage. USART - (Universal Synchronous/Asynchronous Receiver/Transmitter)
SPI - In a computer, a serial peripheral interface (SPI) is an interface that enables the serial (one bit at a time) exchange of data between two devices, one called a master and the other called a slave . An SPI operates in full duplex mode. This means that data can be transferred in both directions at the same time.
GlOANASS - Global Navigation Satellite System. GLONASS is Russia's version of GPS (Global Positioning System)