1. ACOE343 - Real-Time Embedded Processor Systems
Dr. Konstantinos Tatas
Assistant Professor
Office 107, FRC building

2. Course outline (1/5)
Programme of Studies:BSc in Computer Engineering, BSc in Computer Science
Name of the module:ACOE343 - Real-Time Embedded Processor Systems
Target group: Computer Engineering – Computer Science students
Level of the unit:BSc –6th Semester
Entrance requirements: ACOE201
Number of ECTS credits: 6

3. Course outline (1/5) Competences to be developed:
Produce efficient real-time designs using the latest technology of PIC32 and 8051-based microcontrollers and the state-of-art Texas Instruments TMS320C64x DSP processors.
Demonstrate real-time algorithmic design techniques for embedded applications using assembly and C/C++ programming, implementation, hardware debugging and measurement techniques using the available uP and DSP boards.
Write realistic embedded system requirements and specifications

4. Course outline (1/5) Course Description:
Embedded C/C++ and Assembly Languages: Embedded C and assembly for programming the 8051-based microcontrollers. Coverage of C/C++ for programming DSPs. Real-Time Design Techniques.
8051-Based Microcontrollers: The MSC121x Development System, Real-Time Input and Output Applications, Architecture and ISA of the MSC121x microcontroller, Real-Time Embedded Ethernet Applications and Real-Time Data Acquisition Applications.
DSPs: The DSP Development System, Real-Time Input and Output Applications with the DSK, Architecture and ISA of the C64x Processor, Fixed-Point Considerations.
DSP Techniques: FIR and IIR filter Applications. FFT, digital modulation techniques and Applications.
Laboratory Work: Individual or small group experiments based on using a variety of EDA tools for programming, debugging and testing the microcontroller and DSP boards.

5. Course outline (1/5) Textbooks: References: Course webpage:
Hermann Kopetz, "Real-Time Systems: Design Principles for Distributed Embedded Applications", Springer, 2011.
Peter Hintenaus, "Engineering Embedded Systems: Physics, Programs, Circuits", Springer, 2015
Marilyn Wolf, “Computers as components: Principles of embedded computing design”, 3rd edition, Morgan Kaufmann Publishers, 2012
References:
M. Margolis, Arduino Cookbook, O’Reilly
T. Noergaard, Embedded Systems Architecture: A Comprehensive Guide for Engineers and Programmers, Newnes, 2005.
B. DeMuth, Designing Embedded Internet Devices, Newnes, 2002.
L. Edwards, Embedded System Design on a Shoestring, Newnes, 2003.
Course webpage:

6. Course outline (1/5) Assessment: Final: 40% Mid-term Exams: 10%
Laboratory Work: 35%
Assignment/Group project: 15%
Quizzes: 5%

7. Mid-term exams (40%) Microcontrollers: DSPs: Multiple choice questions
Small programs
Assembly/C/either
DSPs:
Mostly C

8. Laboratory work (40%)
Small group experiments with the ChipKit MAX32 PIC-based Arduino
Small group experiments with EdSim 8051 emulator
Small group experiments with the TI DSK
Deliverables:
Lab report (with source code)!!!
Assessment:
Active participation:40%
Methodology/Source code:30%
Board Testing: 20%
Presentation:10%
Labs should be submitted within one week after lab conduct time and grades will be posted on the e-learning website within another week

9. ChipKit MAX32 Microcontroller: PIC32MX795F512L Flash Memory: 512K
RAM Memory: 128K
Operating Voltage: 3.3V
Operating Frequency: 80Mhz
Typical operating current: 90mA
Input Voltage (recommended): 7V to 15V
Input Voltage (maximum): 20V
I/O Pins: 83 total
Analog Inputs: 16
Analog input voltage range: 0V to 3.3V
DC Current per pin: +/-18mA
Advanced peripherals:
10/100 Ethernet MAC
USB 2.0 Full Speed OTG controller
2 CAN controllers.
External Interrupts: Pin 3 (INT0), Pin 2 (INT1), Pin 7 (INT2), Pin 21 (INT3), Pin 20 (INT4)

10. Basic I/O Shield Features 128x32 pixel OLED graphic display
I2C temperature sensor
256Kbit I2C EEPROM
I2C daisy chain connector
4 push buttons
4 slide switches
8 discrete LEDs
4 open drain FET drivers
Analog potentiometer

11. Analog Shield ADS8343: 16 bit, 4 channel Analog to Digital converter
DAC8564: 16 bit, 4 channel Digital to Analog converter
Variable 7.5V bipolar power supply
Fixed 5V bipolar power supply
Breadboard
Can be used with:
TI Analog myPartsKit
Digilent Electronics Explorer Board
chipKIT Uno32*
Arduino Uno

12. Network Shield Features: Usable with the Max32
SMSC LAN /100 Ethernet PHY
RJ45 connector with integral magnetics
USB device and host connectors
Two MCP2551 CAN transceivers
Two 12-pin header connectors for CAN
Two I2C daisy chain connectors
256Kbit I2C EEPROM
KHz oscillator

13. Assignment/Group Project (15%)
8051 emulator or Chipkit MAX32 application implementation
Done in small groups
Different application for each group

14. Typical Semester Outline
Week8
Embedded System requirements and Specifications
Power consumption estimation
Lab7
Week 9:
DSP processors
Lab8
Group project discussion
Quiz3
Week10:
The TI TMS processors
Lab9
Week11:
DSP applications with TI TMS
Lab10
Quiz4
Week12:
Test2
Week13:
Group project presentations
Week 1:
Introduction to Embedded Systems
Lab1:
Week 2:
The Arduino environment
Lab2
Quiz1
Week3:
Lab3
Week4:
The 8051 microcontroller
Lab4
Week5:
Lab5
Week6:
Microcontroller case studies/applications
Lab6
Quiz2
Week 7:
Test1

15. Introduction to Embedded Systems

16. Outline What is an embedded system
Characteristics and Classification of Embedded Systems
Systems-on-a-Chip
Distributed Systems
Internet-of-Things
Embedded Systems Design Challenges
Real-Time Embedded Systems

17. Microprocessors for Embedded systems
Computing systems are everywhere
Most of us think of “desktop” computers
PC’s
Laptops
Mainframes
Servers
But there’s another type of computing system
Far more common...

18. Embedded systems overview
Embedded computing systems
Computing systems embedded within electronic devices
Hard to define. Nearly any computing system other than a desktop computer
Billions of units produced yearly, versus millions of desktop units
Perhaps 50 per household and per automobile
A lot more programming is done for embedded systems than desktop computers or servers
Computers are in here...
and here...
and even here...
Lots more of these, though they cost a lot less each.

19. A “short list” of embedded systems
Anti-lock brakes
Auto-focus cameras
Automatic teller machines
Automatic toll systems
Automatic transmission
Avionic systems
Battery chargers
Camcorders
Cell phones
Cell-phone base stations
Cordless phones
Cruise control
Curbside check-in systems
Digital cameras
Disk drives
Electronic card readers
Electronic instruments
Electronic toys/games
Factory control
Fax machines
Fingerprint identifiers
Home security systems
Life-support systems
Medical testing systems
Modems
MPEG decoders
Network cards
Network switches/routers
On-board navigation
Pagers
Photocopiers
Point-of-sale systems
Portable video games
Printers
Satellite phones
Scanners
Smart ovens/dishwashers
Speech recognizers
Stereo systems
Teleconferencing systems
Televisions
Temperature controllers
Theft tracking systems
TV set-top boxes
VCR’s, DVD players
Video game consoles
Video phones
Washers and dryers
And the list goes on and on

20. Definitions Broad definition: Narrow definition:
Any computer system that is not a general-purpose computer
That would include robots, and all portable devices
Narrow definition:
A computer system (software and hardware) that interacts with its physical environment, mainly without human intervention
That would exclude printers, modems, portable devices such as dvd and mp3 players, etc.

21. Some common characteristics of embedded systems
Single-functioned
Executes a single program, repeatedly
Tightly-constrained
Low cost, low power, small, fast, etc.
Reactive and real-time
Continually reacts to changes in the system’s environment
Must compute certain results in real-time without delay

22. Classification of Embedded Systems
Centralized vs distributed
Real-time vs non real-time
Battery powered vs mains powered
System-on-Chip vs discrete element

23. Are the following embedded systems. If yes, classify them
Are the following embedded systems? If yes, classify them. Which characteristics of an embedded system do they have or do not have?
Printer
DVD player
Mobile phone
Tablet
Netbook/laptop

24. Typical Embedded System Components
Sensors: Allow the system to “read” the environment
Processing Elements: Control of the embedded system
Actuators: Allow the system to act on its environment
Network Connection: Local or internet, allowing exchange of information

25. An embedded system example – Digital camera
Microcontroller
CCD preprocessor
Pixel coprocessor
A2D
D2A
JPEG codec
DMA controller
Memory controller
ISA bus interface
UART
LCD ctrl
Display ctrl
Multiplier/Accum
Digital camera chip
lens
CCD
Single-functioned -- always a digital camera
Tightly-constrained -- Low cost, low power, small, fast
Reactive and real-time -- only to a small extent

26. Embedded Software Development Requires as Much/More Design Effort Than Hardware

27. A System-on-a-Chip: Example
Courtesy: Philips

28. Design at a crossroad System-on-a-Chip
RAM
500 k Gates FPGA
+ 1 Gbit DRAM
Preprocessing
Multi-
Spectral
Imager mC
system
+2 Gbit
DRAM
Recog-
nition
Analog
64 SIMD Processor
Array + SRAM
Image Conditioning
100 GOPS
Embedded applications where cost, performance, and energy are the real issues!
DSP and control intensive
Mixed-mode
Combines programmable and application-specific modules
Software plays crucial role

29. IoT Embedded system with internet connection
Not quite as simple as it sounds
Increased need for security
Safety issues
Direct machine to machine (M2M) communication

30. Case studies of distributed embedded systems
Dr. Konstantinos Tatas

31. Outline Case study 1: RFID Case study 2: Wireless sensor networks
Case study 3: Internet of things

32. RFID Tags Developed to automate the process of object identification
electronic tags (called RFID tags) can be read from a small distance by an RFID reader
An RFID reader does not require a direct line-of-sight to the RFID tag.
The RFID tag stores the unique Electronic Product Code (EPC) of the attached object.

33. RFID Tag dimensions
Since an RFID tag has to be attached to every object, the cost of an RFID tag is a major issue.
RFID tags come in various shapes and sizes and continue to decrease in size
RFID tags are implantable and implants have been approved in humans as well as animals.

34. RFID Reader
The RFID reader can act as a gateway to the Internet and transmit the object identity, together with the read-time and the object location (i.e., the location of the reader) to a remote computer system that manages a large database.
It is thus possible to track objects in real-time
Applications: toll gates, hospitals and large organizations, public transportation systems, tracking of animals, libraries

35. Electronic product code
A typical EPC has a length of 96 bits and contains the following fields:
Header (8 bits): defines the type and the length of all subsequent fields.
EPC Manager (28 bits): specifies the entity (most often the manufacturer) that assigns the object class and serial number in the remaining two fields.
Object Class (24 bits): specifies a class of objects (similar to the optical bar code).
Object Identification Number (36 bits): contains the serial number within theobject class.
The EPC is unique product identification, but does not reveal anything about the properties of the product.
Two things that have the same properties, but are designed by two different manufacturers, will have completely different EPCs.

36. Passive RFID tags
Passive RFID Tags. No power supply. They get the power needed for their operation from energy harvested out of the electric field that is beamed on them by the RFID reader. The energy required to operate a passive tag of the latest generation is below 30 mW and the cost of such a tag is below 5 ¢.
Due to the low level of the available power and the cost pressure on the production of RFID tags, the communication protocols of passive RFID tags do not conform to the standard Internet protocols. Specially designed communication protocols between the RFID tag and the RFID reader that consider the constraints of passive RFID tags have been standardized by the ISO (e.g., ISO C also known as the EPC global Gen 2) and are supported by a number of manufacturers.

37. Active RFID tags Active RFID Tags
have their own on-board power supply
The lifetime of an active tag is limited by the lifetime of the battery
typically in the order of a year.
Active tags can transmit and receive over a longer distance
typically in the order of hundreds of meters,
can have sensors to monitor their environment
sometimes support standard Internet communication protocols.
An active RFID tag resembles a small embedded system
More expensive

39. WSN A set of sensor nodes that each contains a sensor
a microcontroller
a wireless communication controller

40. WSN node
A sensor node can acquire a variety of physical, chemical, or biological signals to measure properties of its environment.

41. WSN node constraints Sensor nodes are resource constrained.
They are powered either by a small battery or by energy harvested from its environment,
have limited computational power, a small memory, and constrained communication capabilities.

42. WSN deployment and operation
a number (from few tens to millions) of sensor nodes are deployed, either systematically or randomly, in a sensor field to form an ad hoc self-organizing network
The WSN collects data about the targeted phenomenon and transmits the data via an ad-hoc multi-hop communication channel to one or more base stations that can be connected to the Internet.

43. WSN function Phase 1: detect neighbors and establish communication
Phase 2: learn about
the arrangement in which the nodes are connected to each other,
the topology of nodes
build up ad-hoc multi-hop communication channels to a base station
In case of the failure of an active node, it must reconfigure the network
Applications:
remote environment monitoring,
surveillance,
medical applications,
ambient intelligence,
military
The utility of a wireless sensor network is in the collective emergent intelligence of all active sensor nodes, not the contribution of any particular node.

44. Primary concern for WSN: energy
A WSN is operational as long as a minimum number of nodes is active and the connectivity of the active nodes to one of the base stations is maintained.
In battery-powered sensor networks, the lifetime of the network depends on the energy capacity of the batteries and the power-consumption of a node.
When a sensor node has depleted its energy supply, it will cease to function and cannot forward messages to its neighbors any more.
The design of the nodes, the communication protocols, and the design of the system and application software for sensor networks are primarily determined by this quest for energy efficiency and low cost.

45. WSN + RFID = the future?
RFID infrastructure for the interconnection of autonomous low-cost RFID-based sensor nodes has been proposed
nodes operate without a battery and harvest the energy either from the environment or the electromagnetic radiation emitted by the RFID reader.
Potential for long-lasting, low-cost ubiquitous sensor nodes that may revolutionize many embedded applications.

46. IoT component: Smart object
A smart object is a cyber-physical system or an embedded system, consisting of a thing (the physical entity) and a component (the computer) that processes the sensor data and supports a wireless communication link to the Internet.
Example: smart refrigerator keeps track of the availability and expiry date of food items and places orders

47. IoT issues
The novelty of the IoT is not in the functional capability of a smart object
Novelty exists in the expected size of billions or even trillions of smart objects that bring about novel technical and societal issues that are related to size.
issues are:
authentic identification of a smart object,
autonomic management and self-organization of networks of smart objects,
diagnostics and maintenance,
intrusion of privacy
Safety issues
Autonomous mobile robots and self-driving cars

48. Key technologies for IoT
low-power wireless communication: no need of a physical connection.
GPS: makes a smart object location- and time-aware

49. Smart object categories
Goal: an autonomic smart object that
has access to a domain specific knowledge base
is empowered with reasoning capabilities to orient itself in the selected application domain.
Based on the capability level of a smart object it can be
activity aware
policy aware
process aware

50. Ultimate vision: smart planet
everyday things around us with an identity in cyberspace capable of acquiring information and intelligence
the world economy and support systems will operate more smoothly and efficiently

51. Social and legal issues in IoT
But the life of the average citizen will also be affected by changing the relation of power between those that have access to the acquired information and can control the information and those that do not.
IoT devices can be hacked with significant dangers to safety and property

52. IoT drivers
The IoT should extend the interoperability of the internet to the universe of heterogeneous smart objects.
Iot must establish a uniform access pattern to things in the physical world.

53. Logistics
The first commercial application of a forerunner of the IoT, the RFID is in the area of logistics
There are many quantitative advantages in using RFID technology in supply-chain management:
the movement of goods can be tracked in real-time,
shelf space can be managed more effectively
inventory control is improved
the amount of human involvement in the supply chain management is reduced considerably.

54. Energy savings
Already today, embedded systems contribute to energy savings in many different sectors of our economy and our life.
increased fuel efficiency of automotive engines,
improved energy-efficiency of household appliances,
reduced loss in energy conversion
The future: of IoT devices opens many new opportunities for energy savings:
Smart buildings: individual climate and lighting control in residential buildings
Smart grids: reduced energy loss in transmission by the installation of smart grids,
Smart meters: better coordination of energy supply and energy demand
Other energy savings:
Physical meetings replaced by virtual meetings
delivery of information goods such as the daily paper, music, and videos by the Internet

55. Security and safety
Automated IoT based access control systems to buildings and homes
IoT-based surveillance of public places
Smart passports and IoT based identifications (e.g., a smart key to access a hotel room or a smart ski lift ticket)
Car-to-car and car-to-infrastructure communication will alert the driver of dangerous traffic scenarios

56. Industrial
computerized observation and monitoring of industrial equipment
reduces maintenance cost
improves the safety in the plant
A smart object can monitor its own operation and call for preventive or spontaneous maintenance in case a part wears out or a physical fault is diagnosed
Automated fault-diagnosis and simple maintenance are absolutely essential prerequisites for the wide deployment of the IoT technology in the domain of ambient intelligence.

57. Medical
The wide deployment of IoT technology in the medical domain is anticipated.
Health monitoring (heart rate, blood pressure, etc.)
precise control of drug delivery by a smart implant
Body area networks that are part of the clothing can monitor the behavior of impaired persons and send out alarm messages if an emergency is developing.
Smart labels on drugs can help a patient to take the right medication at the right time and enforce drug compliance.
Example: A heart pacemaker can transmit important data via a Bluetooth link to a mobile phone that is carried in the shirt pocket. The mobile phone can analyze the data and call a doctor in case an emergency develops.

58. Technical issues: internet integration
Guaranteeing the safety and information security of IoT-based systems is considered to be a difficult task.
Many smart objects will be protected from general Internet access by a tight firewall to avoid that an adversary can acquire control of a smart object.

59. Naming and identification
A well-thought-out naming architecture in order to be able to identify a smart object and to establish an access path to the object is essential.
Isolated Objects. The following three different object names have to be distinguished when we refer to the simple case of an isolated object:
Unique object identifier (UID) refers to the physical identity of a specific object.
The Electronic Product Code (EPC) of the RFID community is such a UID.
Object type name refers to a class of objects that ideally have the same properties.
Object role name. In a given use context, an object plays a specific role that is denoted by the object role name.

60. Composite object naming
Composite Objects. Whenever a number of objects are integrated to form a composite object, a new whole, i.e., new object is created that has an emerging identity that goes beyond the identities of the constituent objects.
The composite object resembles a new concept (see Sect ) that requires a new name.

61. IoT vs cloud computing
Smart objects that have access to the Internet can take advantage of services that are offered by the cloud
The division of work between a smart object and the cloud will be determined, to a considerable degree, by privacy and energy considerations
If the energy required to execute a task locally is larger than the energy required to send the task parameters to a server in the cloud, then the task is a candidate for remote processing.
However, there are other aspects that influence the decision about work distribution: autonomy of the smart object, response time, reliability, and security.

62. Processing Elements used in Embedded Systems
Microcontroller:
Cheap
Optimized for control applications
Low processing power
Low power consumption
General-Purpose Processor:
More expensive
Medium processing power
Suitable but not optimized for any application
High power consumption
Digital Signal Processor:
Optimized for DSP applications (high-end audio, video and image processing)
FPGA:
Good processing power
Longer development time
Medium cost
ASIC:
High processing power
Very low power consumption
Expensive at low volume
Optimized for specific application (hardware accelerators)
Long development time

63. Design challenge – optimizing design metrics
Obvious design goal:
Construct an implementation with desired functionality
Key design challenge:
Simultaneously optimize numerous design metrics
Design metric
A measurable feature of a system’s implementation
Optimizing design metrics is a key challenge

64. Design challenge – optimizing design metrics
Common metrics
Unit cost: the monetary cost of manufacturing each copy of the system, excluding NRE cost
NRE cost (Non-Recurring Engineering cost): The one-time monetary cost of designing the system
Size: the physical space required by the system
Performance: the execution time or throughput of the system
Power: the amount of power consumed by the system
Flexibility: the ability to change the functionality of the system without incurring heavy NRE cost

65. Design challenge – optimizing design metrics
Common metrics (continued)
Time-to-prototype: the time needed to build a working version of the system
Time-to-market: the time required to develop a system to the point that it can be released and sold to customers
Maintainability: the ability to modify the system after its initial release
Correctness, safety, many more

66. Design metric competition -- improving one may worsen others
Expertise with both software and hardware is needed to optimize design metrics
Not just a hardware or software expert, as is common
A designer must be comfortable with various technologies in order to choose the best for a given application and constraints
Size
Performance
Power
NRE cost
Microcontroller
CCD preprocessor
Pixel coprocessor
A2D
D2A
JPEG codec
DMA controller
Memory controller
ISA bus interface
UART
LCD ctrl
Display ctrl
Multiplier/Accum
Digital camera chip
lens
CCD

67. Time-to-market: a demanding design metric
Time required to develop a product to the point it can be sold to customers
Market window
Period during which the product would have highest sales
Average time-to-market constraint is about 8 months
Delays can be costly
Revenues ($)
Time (months)

68. Losses due to delayed market entry
Simplified revenue model
Product life = 2W, peak at W
Time of market entry defines a triangle, representing market penetration
Triangle area equals revenue
Loss
The difference between the on-time and delayed triangle areas
On-time Delayed
entry entry
Peak revenue
Peak revenue from delayed entry
Market rise
Market fall W 2W
Time D
On-time
Delayed
Revenues ($)

69. Losses due to delayed market entry (cont.)
Area = 1/2 * base * height
On-time = 1/2 * 2W * W
Delayed = 1/2 * (W-D+W)*(W-D)
Percentage revenue loss = (D(3W-D)/2W2)*100%
Try some examples
On-time Delayed
entry entry
Peak revenue
Peak revenue from delayed entry
Market rise
Market fall W 2W
Time D
On-time
Delayed
Revenues ($)
Lifetime 2W=52 wks, delay D=4 wks
(4*(3*26 –4)/2*26^2) = 22%
Lifetime 2W=52 wks, delay D=10 wks
(10*(3*26 –10)/2*26^2) = 50%
Delays are costly!

70. Real-time (reactive) systems
Systems that are bound by a real-time constraint (“deadline”) in their operation
If the deadline is not met it is usually considered a system failure, even if the output is eventually correct
Deadlines are usually relative to an event
Hard deadlines: Anti-lock brakes,
Soft deadlines: Digital video
Not the same as high-performance systems, because often running faster than real-time requirement is not necessary or desired

71. Real-time constraints
te + to < tc
te: execution time
to: overhead time
tc: constraint time

72. Example
Assuming a real-time system that processes samples at a f= 10 MHz sampling rate, and a to= 20 ns, select the most appropriate implementation among the following:
A processor running at 500 MHz, requiring 100 cycles at a cost of 50$
An FPGA running at 200 MHz, requiring 10 cycles at a cost of 60$
A DSP running at 500 MHz, requiring 20 cycles at a cost of 100$
An ASIC running at 2 GHz, requiring 20 cycles at a cost of 500$