KEMBAR78
Embedded system custom single purpose processors | PPT
Alpha Breathing : (2 Mins)

The three steps for alpha breathing are
• Breathe in
• Breathe out
• Hold
(Repeat the three steps for 8 times)
Chapter 4 Custom Single
Purpose Processors
Processor
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Digital circuit that performs a computation tasks
Controller and datapath
General-purpose: variety of computation tasks
Single-purpose: one particular computation task
Custom single-purpose: non-standard task
A custom single-purpose processor may be
– Fast, small, low power
– But, high NRE, longer time-to-market, less flexible
Digital Camera
CMOS transistor on silicon
•

Transistor
– The basic electrical component in digital systems
– Acts as an on/off switch
– Voltage at “gate” controls whether current flows from source to drain
– Don’t confuse this “gate” with a logic gate
CMOS transistor implementations

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•
•

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Complementary Metal Oxide Semiconductor
We refer to logic levels
– Typically 0 is 0V, 1 is 5V
Two basic CMOS types
– nMOS conducts if gate=1
– pMOS conducts if gate=0
– Hence “complementary”
Basic gates
– Inverter, NAND, NOR
Basic gates
Basic logic gates
Combinational Logic Design
Combinational Circuit
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•

A combinational circuit is a digital circuit whose output is purely a
function of its current inputs;
such a circuit has no memory of past inputs.
Sequential Logic Design
Design task
• Define system functionality
• Convert functionality to physical implementation while
• Satisfying constrained metrics
• Optimizing other design metrics
• Designing embedded systems is hard
• Complex functionality
• Millions of possible environment scenarios
• Given this implementation model
– Sequential logic design quickly reduces to combinational logic design
Improving Productivity
Brain Activation: (2 mins)
Survey and Reading by students (18 mins.)

Survey:
Define custom single purpose processors.
Mention the components of combinational logic.
Mention the components of sequential logic.
List out the steps involved in creating a data path.
List out the steps in creating a controller.
 
Reading:
1. What are the steps in creating FSM?
2. List out the basic logic gates?
Guided Reading with hints
Page No.: 68-74
Discussion (9 mins.)
Reconstruct – Mind map (7 mins.)
Summary (5 mins.)
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•
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•

Custom single-purpose processors
– Combinational logic
– Sequential logic
• Sequential components
• Creating data path and controller
• FSM
– Hardware
• Processor
• CMOS transistor on silicon
Straightforward design techniques
Can be built to execute algorithms
Typically start with FSMD
Optimizing Single purpose processors
CAD tools can be of great assistance
Gazing/Rote memory: (2 mins)

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•
•
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Combinational logic
Combinational logic components
Sequential logic
Sequential logic components
Custom single-purpose processor design
RT-level custom single-purpose processor design
Assessment (MCQ And higher order
questions)
1. Basic logic gates _________.
(a) NAND
(b) NOR
(c) NOT
(d) EXNOR
2. Drivers ,Inverters are __________ .
(a) OR and XOR
(b) AND and NOT
(c) XOR and XNOR
(d) OR and AND
3. CMOS stands for ___________ .
(a) Complementary Metal Oxide Semiconductor
(b) Complementary Metal Oxide Stub
(c) Complementary Metal Oxide Semi transistor
(d) None
4. A multiplexer is sometimes called as
.

(a) selector
(b) distributor
(c) transistor
(d) collector
5. The components of combinational logic is ______________
.
(a) Multiplexer
(b) Decoder
(c) ALU
(d) All the above
Two mark Questions:
State the benefits of custom single purpose processors.
Mention some of the combinational logic gates.
Define combinational logic design.
Mention the advantages and disadvantages in CMOS transistors.
Define the performance metric for throughput and time in embedded system.

[C] Descriptive Questions:
Explain combinational logic.
Differentiate the features of pMOs, CMOS and nMOS transistors.

Embedded system custom single purpose processors

  • 1.
    Alpha Breathing :(2 Mins) The three steps for alpha breathing are • Breathe in • Breathe out • Hold (Repeat the three steps for 8 times)
  • 3.
    Chapter 4 CustomSingle Purpose Processors
  • 4.
    Processor • • • • • • • Digital circuit thatperforms a computation tasks Controller and datapath General-purpose: variety of computation tasks Single-purpose: one particular computation task Custom single-purpose: non-standard task A custom single-purpose processor may be – Fast, small, low power – But, high NRE, longer time-to-market, less flexible
  • 6.
  • 7.
    CMOS transistor onsilicon • Transistor – The basic electrical component in digital systems – Acts as an on/off switch – Voltage at “gate” controls whether current flows from source to drain – Don’t confuse this “gate” with a logic gate
  • 8.
    CMOS transistor implementations • • • • ComplementaryMetal Oxide Semiconductor We refer to logic levels – Typically 0 is 0V, 1 is 5V Two basic CMOS types – nMOS conducts if gate=1 – pMOS conducts if gate=0 – Hence “complementary” Basic gates – Inverter, NAND, NOR
  • 9.
  • 10.
  • 11.
  • 13.
    Combinational Circuit • • A combinationalcircuit is a digital circuit whose output is purely a function of its current inputs; such a circuit has no memory of past inputs.
  • 15.
    Sequential Logic Design Designtask • Define system functionality • Convert functionality to physical implementation while • Satisfying constrained metrics • Optimizing other design metrics • Designing embedded systems is hard • Complex functionality • Millions of possible environment scenarios • Given this implementation model – Sequential logic design quickly reduces to combinational logic design
  • 16.
  • 18.
  • 20.
    Survey and Readingby students (18 mins.) Survey: Define custom single purpose processors. Mention the components of combinational logic. Mention the components of sequential logic. List out the steps involved in creating a data path. List out the steps in creating a controller.   Reading: 1. What are the steps in creating FSM? 2. List out the basic logic gates? Guided Reading with hints Page No.: 68-74
  • 21.
  • 22.
    Reconstruct – Mindmap (7 mins.)
  • 23.
    Summary (5 mins.) • • • • • • Customsingle-purpose processors – Combinational logic – Sequential logic • Sequential components • Creating data path and controller • FSM – Hardware • Processor • CMOS transistor on silicon Straightforward design techniques Can be built to execute algorithms Typically start with FSMD Optimizing Single purpose processors CAD tools can be of great assistance
  • 24.
    Gazing/Rote memory: (2mins) • • • • • • Combinational logic Combinational logic components Sequential logic Sequential logic components Custom single-purpose processor design RT-level custom single-purpose processor design
  • 25.
    Assessment (MCQ Andhigher order questions) 1. Basic logic gates _________. (a) NAND (b) NOR (c) NOT (d) EXNOR 2. Drivers ,Inverters are __________ . (a) OR and XOR (b) AND and NOT (c) XOR and XNOR (d) OR and AND
  • 26.
    3. CMOS standsfor ___________ . (a) Complementary Metal Oxide Semiconductor (b) Complementary Metal Oxide Stub (c) Complementary Metal Oxide Semi transistor (d) None 4. A multiplexer is sometimes called as . (a) selector (b) distributor (c) transistor (d) collector 5. The components of combinational logic is ______________ . (a) Multiplexer (b) Decoder (c) ALU (d) All the above
  • 27.
    Two mark Questions: Statethe benefits of custom single purpose processors. Mention some of the combinational logic gates. Define combinational logic design. Mention the advantages and disadvantages in CMOS transistors. Define the performance metric for throughput and time in embedded system. [C] Descriptive Questions: Explain combinational logic. Differentiate the features of pMOs, CMOS and nMOS transistors.