Prologue TO LOW-Control Plan.


104 views
Uploaded on:
Description
Versatile Electronics (PC, PDA, Wireless) IC Cost (Packaging and Cooling) Reliability ... Power: Portable Applications. The business sector of compact applications is ...
Transcripts
Slide 1

Prologue TO LOW-POWER DESIGN

Slide 2

Why Low-Power Devices? Useful reasons (Reducing power necessities of high throughput versatile applications) Financial reasons (Reducing bundling costs and accomplishing memory reserve funds) Technological reasons (Excessive warmth keeps the acknowledgment of high thickness chips and restricts their functionalities)

Slide 3

Application Fields Portable Electronics (PC, PDA, Wireless) IC Cost (Packaging and Cooling) Reliability (Electromigration, Latch-up) Signal Integrity (Switching Noise, DC Voltage Drop) Thermal Design Ultra-low-control applications Space missions (scaled down satellites)

Slide 4

Different Constraints for Different Application Fields Portable gadgets: Battery life-time Telecom and military: Reliability (lessened force diminishes electromigration, consequently builds unwavering quality) High volume items: Unit cost (reduced power diminishes bundling cost)

Slide 5

Design Technology Trend

Slide 6

Driving Forces for Low-Power: Portable Applications The business sector of convenient applications is becoming quickly. Worldwide Market for Cellular Phones

Slide 7

Driving Forces for Low-Power: Deep-Submicron Technology ADVANTAGES Smaller geometries Higher clock frequencies DISADVANTAGES Higher force utilization Lower unwavering quality

Slide 8

Driving Forces for Low-Power: Battery Limitations Battery greatest force and limit increments 10%-15% every year Increasing hole regarding power request

Slide 9

What has worked up to now? Voltage and procedure scaling Design approachs Power-mindful configuration streams and apparatuses, exchange zone for lower power Architecture Design Power down systems Clock gating, dynamic force administration Dynamic voltage scaling in view of workload Power cognizant RT/rationale blend Better cell library outline and resizing techniques Cap. decrease, limit control, transistor format

Slide 10

Opportunities for Power Savings

Slide 11

Realistic Estimation Expectations

Slide 12

Peak power P(t) RMS power Average force Energy t Power Metrics Average force: Related to battery lifetime. Crest power: Related to unwavering quality and warm disappointment RMS power: Related to cycle-by-cycle power Energy=power  time: Related to power-delay item.

Slide 13

Why CMOS? V DD Intrinsically low power expending (when the info is static, there is no force utilization) Reference innovation Ease of configuration. PMOS V in V out NMOS Basic CMOS setup V SS

Slide 14

A NMOS entryway Polysilicon or Metal Oxide Gate Source Drain p n

Slide 15

A one-sided NMOS door V GS >0 + p n

Slide 16

A one-sided NMOS door V GS >0 + p n

Slide 17

A parallel plate capacitance A one-sided NMOS door V GS =V Tn + p n When V GS  V Tn , the n-channel is produced and the gadget can begin operation by applying a positive V DS

Slide 18

Standard (Non-Adiabatic) Capacitance Change

Slide 19

Energy Stored in C

Slide 20

Energy Supplied by the Battery

Slide 21

Heat = Energy Dissipated (Non-Adiabatic)

Slide 22

Quasi-Adiabatic Charging of C

Slide 23

Sources of Power Consumption in CMOS

Slide 24

Power Dissipation in CMOS Circuits P absolute = P exchanging + P hamper P spillage Due to charging and releasing capacitors (dynamic force utilization) Due to direct ways Due to spilling diodes and transistors %75 %20 %5

Slide 25

C DD  C GND Inverter: A Basic CMOS Gate

Slide 26

Inverter Analysis

Slide 27

Inverter Analysis

Slide 28

Energy Consumed (relate d to Battery Power) Energy expended because of a complete cycle 0 1 0.

Slide 29

Dynamic Power Consumption (identified with Battery Power) Average force utilization by a hub cycling at every period T : (every period has a 0 1 or a 1  0 move) Average force devoured by a hub with incomplete action (just a portion  of the periods has a move)

Slide 30

Dynamic Power Consumption (identified with Inverter) Average force utilization by a hub cycling at every period T : (every period has a 0 1 or a 1  0 move) Average force devoured by a hub with halfway action (just a part  of the periods has a move)

Slide 31

C L = C eff Dynamic Power Consumption Define successful capacitance C eff : To minimize exchanging power Reduce V DD Reduce C eff

Slide 32

Factors Influencing C eff Circuit capacity Circuit innovation Input probabilities Circuit topology

Slide 33

Some Basic Definitions Signal likelihood of a sign g(t) is given by Signal action of a rationale signal g(t) is given by where n g (t) is the quantity of moves of g(t) in the time interim between –T/2 and T/2 .

Slide 34

Factors Influencing C eff : Circuit Function Assume that there are M commonly autonomous signs g 1 , g 2 ,...g M each having a sign likelihood P i and a sign action An i , for i  n. For static CMOS, the sign likelihood at the yield of a door is resolved by likelihood of 1s (or 0s) in the rationale portrayal of the entryway P 1 P 1 P 1 P 2 1-(1-P )(1-P 2 ) P 1-P 1 P 2 P 2

Slide 35

Factors Influencing C eff : Circuit Function (Static CMOS) Transistors associated with the same information are turning on and off at the same time when the info changes C L of a static CMOS door is charged to V DD at whatever time a 0  1 move at the yield hub is required. C L of a static CMOS entryway is released to ground whenever a 1  0 move at the yield hub is required. NOR Gate

Slide 36

A Y B Factors Influencing C eff : Circuit Function (Static CMOS) Two-information NOR door Assume stand out info move per cycle is permitted Assume inputs are equiprobable: p A =p B =1/2. The likelihood for the yield to be 1 is p Y =(1-p A )(1-p B )=1/4 The likelihood for the yield to be 0 is p Y \'=1-p Y =3/4

Slide 37

Factors Influencing C eff : Circuit Function (Static CMOS) State move chart of the NOR door

Slide 38

A Y B Factors Influencing C eff : Circuit Function (Static CMOS) Two-information X OR entryway Assume one and only info move per cycle is permitted Assume inputs are equiprobable: p A =p B =1/2. The likelihood for the yield to be 1 is p Y =(1-p A ) p B + (1-p B ) p A =1/2 The likelihood for the yield to be 0 is p Y \'=1-p Y = 1/2

Slide 39

Factors Influencing C eff : Circuit Function (Static CMOS) State move graph of the NOR entryway

Slide 40

f Factors Influencing C eff : Circuit Function ( Dynamic CMOS) At every cycle, MD is precharged to V DD. C L is precharged to V DD at every clock cycle It is released to ground at whatever time a 1  0 move at the yield hub is required. MD

Slide 41

A Y B Factors Influencing C eff : Circuit Function ( Dynamic CMOS) Two-info NOR entryway Assume stand out information move per cycle is permitted Assume inputs are equiprobable: p A =p B =1/2. The likelihood for the yield to be released is p Y " = 3/4 The likelihood of C L to be re-charged at the following cycle is p Y " .

Slide 42

Factors Influencing C eff : Circuit Function (Dynamic versus Static )  dynamic CMOS   static CMOS : C eff (dynamic CMOS)  C eff (static CMOS) Power because of glitching is much littler in element CMOS than it is in static CMOS. In static CMOS, the move likelihood relies on upon both info probabilities and past state. In element CMOS, the move likelihood relies on upon exclusively include probabilities. In static CMOS, the entryway yield does not switch if the inputs don\'t change between ensuing cycles. In element CMOS, the door yield may switch regardless of the fact that the inputs don\'t change between resulting cycles.

Slide 43

A Y B Factors Influencing C eff : Input Probabilities (Static CMOS) Two-info NOR entryway Assume stand out information move per cycle is permitted Assume inputs are not equiprobable: p A , p B The likelihood for the yield to be 1 is p Y =(1-p A )(1-p B ) The likelihood for the yield to be 0 is p Y \'=1-p Y

Slide 44

Factors Influencing C eff : Input Probabilities (Static CMOS) The likelihood for the yield of a NOR door to have a 0 1 move:

Slide 45

Factors Influencing C eff : Input Probabilities (Static CMOS) Signal likelihood figuring: For every information flag and entryway yield in the circuit, dole out a novel variable Starting from at the inputs and continuing to the yields, compose the expression for the yield of every entryway as an element of its information expression Suppress all examples in an offered expression to acquire the right likelihood for that sign (Recall that a type of a twofold number is additionally a double number)

Slide 46

Factors Influencing C eff : Input Probabilities (Static CMOS) Signal action computation: Boolean Difference It implies the condition under which yield f is sharpened to information x i If the essential inputs to capacity f are not spatially corresponded, the sign action at f is

Slide 47

Factors Influencing C eff : Input Probabilities (Static CMOS) Signal action through fundamental doors P 1 , A 1 P 2 A 1 + P 1 A 2 P 1 , An A P 2 , A 2 P 1 , A (1-P 2 ) A 1 + (1-P 1 ) A 2 P 2 , A 2 Signal action is utilized to decide dynamic force due to glitches.

Slide 48

Factors Influencing C eff : Circuit Topology Circuit topology may have high effect on C eff Example: Chain and Tree usage of a four information NAND entryway Assume static CMOS Assume all inputs are equiprobable.

Slide 49

Factors Influencing C eff : Circuit Topology Globally chain usage has a lower exchanging movement in the static conduct of the circuit. Timing skew between signs may bring about perils bringing about additional force dissemination. Consider 1110 1011 in chain circuit with unit postponement of every entryway.

Slide 50

Factors Influencing C eff : Circuit Topology The chain circuit experiences dangers,

Recommended
View more...