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Lesson 2: Embedded Systems
- Introduction and
Architectural Overview
–Hardware Elements in
Embedded Systems
Typical Embedded System Hardware
elements(Units)
P5 Figure 1.1
Embedded System

Has three main components:
1. It has hardware—to give computer like
functionalities
2. It has main application software—generally into
flash or ROM and the application software
performs concurrently the number of tasks
3. It has a real time operation system(RTOS)—which
supervises the application software tasks running
on the hardware and organizes the accesses to
system resources according to priorities and timing
constraints of tasks in the system
Embedded System

Has three constraints:
1. available system-memory
2. available processor speed
3. the need to limit power dissipation
when running the system
continuously in cycles of the system
start, wait for events, wake-up and
run, sleep and stop
Embedded System

Has some design constraints:
1. Performance
2. Power
3. Size
4. non-recurring design cost
5. manufacturing cost
1. Processor at the System

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A processor has two essential units: Program
Flow and data path Control Unit (CU) and
Execution Unit (EU)
The CU includes a fetch unit for fetching
instructions from memory. The EU has circuits
that implement the instructions pertaining to data
transfer operations and data conversion from one
form to another. The EU includes the Arithmetic
and Logical Unit (ALU) and also the circuits that
execute instructions for a program control task,
say, halt, interrupt, or jump to another set of
instructions. It can also execute instructions for a
call or branch to another program and a call to
function.
System designer considerations
System designer considerations
Clock frequency in MHz and processing speeds
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
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MIPS – Million Instructions Per Second
MFLOPS – Million Floating Point Operations
Per Second
Dhrystone/s – Number of times a benchmark
program called Dhrystone program can run
per second.[1MIPS = 1757 Dhrystone/s]
1. Processor at the System

An embedded system processor chip
can be one of the following:
(i) General Purpose Processor (GPP)
1. Processor at the System

(i) a. General purpose microprocessor
◊ Any CPU must possess the following basic
functional units:
▪ A control unit to fetch and control the
sequential processing of a given command or
instruction and for communication with the
rest of the system
▪ An ALU for the arithmetic and logical
operations on the bytes or words.
Typically a Motorola 68HCxxx or Intel 80x86, Intel i860 family,
Sparc, PowerPC
or
1. Processor at the System

(i) b. Microcontroller -- Intel, Motorola,
Hitachi, TI, and Philips, ARM, …
◊ Just as a microprocessor is the most essential part of a
computing system, a microcontroller is the most essential
component of a control or communication circuit. A
microcontroller is a single-chip VLSI unit which, though having
limited computational capabilities, possesses enhanced inputoutput capabilities and a number of on-chip functional units.
Typically an Intel®: MCS® 51, 151, 251, 96, 196 or 296
Motorola : - 68HC11, 68HC12, 68HC16, or MCORE M2001
or
1. Processor at the System

(i) Subunits in a Microcontroller
P11 Figure 1.2
1. Processor at the System
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(i) c. Use of General Purpose
Processors and Microcontrollers
as VLSI component on a chip
Typically ARM 7, ARM 9, ARM 11,
Intel XScale, Texas OPMAP 5910 or
Power PC 750x
or
1. Processor at the System
P12 Figure 1.3
1. Processor at the System

(i) d. DSP(Digital Signal Processor)
Typically a Texas InstrumentsC28x Series, C54xx or C64xx
or Analog Devices SHARC or
Motorola 5600xx
or
1. Processor at the System

(i) e. Media processor
TI DSP TMS320DM310 or Trimedia
Phillips Media Processor 1x00
series for Processing Streaming and
Data Networks and Image, Video
and Speech: PNX1300 and PNX
1500 (2002)
1. Processor at the System
A Media Processor PNX 1x00
1. Processor at the System
(ii) Application Specific System
Processor (ASSP)
Typically a set up box processor
or mpeg video-processor or
network application processor
or mobile application processor
or
1. Processor at the System
(iii) Application Specific Instruction
processor (ASIP)
Typically a processor for speech
processing, adaptive filtering,
encrypting and decrypting,
communication protocol stack
processing applications
Recent Announcement in
Processor’s Technology
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On April 14, 2003 INTEL
announced replacement of 0.12µm
with 0.09µm (90 nm) processor
operating at 3 GHz with system
buses operating at 800 MHz
Now Intel, TI and Xilinx are 3
companies with 90 nm processors
New Innovation Examples
1. Use of on-chip Compilers: for example,
introduction of its first compilers to help
developers write applications for Intel®
Personal Internet Client Architecturebased PDAs, cell phones and other
wireless devices using Intel® XScale™
technology-based processors [Intel
Corporation, Press Release: July 14,
2003]
New Innovation Examples
2. World's First GSM TV
Phone - posted on September
19, 2003 1:17 PM EDT
New Innovation Examples
3. SYSTEM-ON-CHIP
Embedding: Multiple
processors, memories, multiple
standard source solutions (IP
Cores), Logic and analog units
New Innovation Example ––Mobile
Phone on a SoC
P40 Figure 1.10
New Innovation Examples
4. Use of IPs (Intellectual Property):
High Level Components with gate level
sophistication circuit much above
level of counters and registers. For
examples, USB port controller and
Wireless 802.11 interface
New Innovation Examples
4. Use of IPs:
▪ An IP may provide hardwared implementable
design of a transform or of an encryption algorithm
or a deciphering algorithm
▪ An IP may provide a design for adaptive filtering of
a signal
▪ An IP may provide full design for implementing
Hyper Text Transfer Protocol (HTTP) or File
Transfer Protocol (FTP) to transmit a web page or
a file on the Internet
▪ An IP may be designed for the PCI or USB bus control
New Innovation Examples
5. Use of Accelerator
Cores: For example Java
Accelerator Nazonin
Communications Java codes
run 15 to 60 Times fast, Video
Accelerator for fast Video
processing
New Innovation Examples
6. Use of FPGAs cum Processor
Cores: (1) FPGA 125136 Logic
Cells along with the Four IBM
PowerPC processors
[Exemplary Application:
System with a Data Encryption
Engine at 1.5 Gbps]
New Innovation Examples
7. Use of Xilinx Spartan-3
90 nm based FPGAs with
Power PCs (released on April
14, 2003 )
New Innovation Examples
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8. Network Processor (2002)
Intel INXP4xx builds Embedded
Systems for Instrumentation with
SOHO and SME communication
applications such as residential
broadband gateways, enterprise
wireless access points and integrated
access of the devices quickly and
efficiently
New Innovation Examples
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9. Mobile Processor (March 2003)
‘Centrino', 'Intel's new mobile
technology includes a new mobile
processor, related chipsets and
802.11 wireless network functions
and wireless Internet Connectivity
Summary

We learnt
(i) overview of hardware elements,
(ii) types of the processor(s) used
in the systems: general purpose
processor, microcontroller, DSP,
Media processor, ASIP, ASIP and
multi-processor, …
(iii) exemplary new innovations
End of Lesson 2