digital signal processor overviewoverview. 2 signal processing specialized adc 2d...
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Digital Signal Digital Signal ProcessorProcessor
Digital Signal Digital Signal ProcessorProcessorOverviewOverviewOverviewOverview
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Signal ProcessingSignal Processing
SpecializedSpecializedADC
2D
01101110001010110100010110111000101011010001
10111010010001010100111101110100100010101001110101010111000101010011101010101110001010100111
ADCADC
1D
Real-time?Real-time?
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Real-time tasks
Real-timeReal-time Processing Processing
Example: Example: 100-tap FIR filter100-tap FIR filter è è eseguito real-time se si è in grado di eseguito real-time se si è in grado di completare l’operazione di filtraggio completare l’operazione di filtraggio entro due istanti di capionamento entro due istanti di capionamento successivi:successivi:
99
0k
knxkany
La definizione di Real-time Processing dipende dal contesto applicativo
Processing Time Waiting Time
Sample TimeSample Timenn n+1n+1
WTPT
ST
WT WT 0 0
4
Analog Signal ProcessingAnalog Signal Processing
Specialized Specialized HWHW
1D
ASICASIC
2D
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Le tolleranzetolleranze associate a questi componenti analogici, la temperaturatemperatura, le variazioni variazioni di voltaggiodi voltaggio e le vibrazioni meccanichevibrazioni meccaniche possono drammaticamente indurre effetti
non prevedibili sul circuito analogico.
Le tecniche di processing analogico si avvalgono di componenti come: ResistorsResistors, , CapacitorsCapacitors e e InductorsInductors.
Analog Signal ProcessingAnalog Signal Processing
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ADC
2D
01101110001010110100010110111000101011010001
10111010010001010100111101110100100010101001110101010111000101010011101010101110001010100111
Digital Signal ProcessingDigital Signal Processing
Specialized Specialized CPUCPU
ADCADC
Specialized Specialized HWHW
DSPDSP
FPGAFPGA
LW R1, a(R4R4)LW R2, b(R4R4)ADD R3,R1,R2SW c(R4R4),R3
ASICASIC
1D
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FIR Filter with Linear PhaseFIR Filter with Linear Phase
Le attuali tecniche di processing digitale sono così potenti che in particolari ambiti
applicativi, è quasi impossibile, per le tecniche di processing analogiche ottenere
performance comparabili.
Adaptive FiltersAdaptive Filters
Digital Signal ProcessingDigital Signal ProcessingFIR FilterFIR Filter
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Digital Signal ProcessingDigital Signal Processing
Change Change applicationsapplications
Correct Correct applicationsapplications
Update Update applicationsapplications
Easy
Reduces
Noise susceptibilityNoise susceptibilityDevelopment timeDevelopment time
Power consumptionPower consumption
Cost
ProgrammaProgrammable ble
HardwareHardware
DSPDSPFPGAFPGA
ProgrammabilitàProgrammabilità
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High frequency signalsHigh frequency signals cannot be processed digitally because of two reasons:
Digital Signal ProcessingDigital Signal ProcessingLimiti degli ADCLimiti degli ADC
Le applicazioni diventano troppo Le applicazioni diventano troppo complesse per essere elaborate in complesse per essere elaborate in
Real-timeReal-time
Analog to Digital Converters (ADC Analog to Digital Converters (ADC ) non lavorano ad alte frequenze) non lavorano ad alte frequenze
ADC
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Digital Signal ProcessorDigital Signal ProcessorDSP vs. GPPDSP vs. GPP
General Purpose Processor General Purpose Processor (GPP)(GPP)Large memoryLarge memory
Advanced operating Advanced operating systemssystems
Processing of many “high” Processing of many “high” frequency signals in real-timefrequency signals in real-time
Cost savingCost saving Smaller sizeSmaller size
Low power consumptionLow power consumption
Digital Signal Processor Digital Signal Processor (DSP)(DSP)
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Algorithm Equation
Finite Impulse Response Filter
M
kk knxany
0
)()(
Infinite Impulse Response Filter
N
kk
M
kk knybknxany
10
)()()(
Convolution
N
k
knhkxny0
)()()(
Discrete Fourier Transform
1
0
])/2(exp[)()(N
n
nkNjnxkX
Discrete Cosine Transform
1
0
122
cos).().(N
x
xuN
xfucuF
La Somma di Prodotti (SOPSOP) è la base di molti algoritmi tipici per DSP:
Digital Signal ProcessorDigital Signal ProcessorAlgoritmo SOPAlgoritmo SOP
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I processori DSP sono ottimizzati per operazioni di somma e moltiplicazione. Moltiplicazioni
e addizioni sono eseguite con hardware specializzati e completate in un ciclo di clock.
HardwaHardwarere
MicrocoMicrocodede
10111011x 1110x 1110
1001101010011010
10111011x 1110x 1110
000000001011.1011.1011..1011..1011...1011...
1001101010011010
Cycle 1Cycle 1Cycle 2Cycle 2Cycle 3Cycle 3Cycle 4Cycle 4
Cycle 5Cycle 5
Digital Signal ProcessorDigital Signal ProcessorHardware vs. MicrocodeHardware vs. Microcode
Example: Example: 4-bit multiply4-bit multiply
(unsigned)(unsigned)
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Parameter
Arithmetic format
Extended floating point
Extended Arithmetic
Performance (peak)
Number of hardware multipliers
Number of registers
Internal L1 program memory cache
Internal L1 data memory cache
Internal L2 cache
32-bit
N/A
40-bit
1200MIPS
2 (16 x 16-bit) with 32-bit result
32
32K
32K
512K
32-bit
64-bit
40-bit
1200MFLOPS
2 (32 x 32-bit) with 32 or 64-bit result
32
32K
32K
512K
TMS320C6211 (@150MHz)
TMS320C6711 (@150MHz)
C6711 Datasheet: C6711 Datasheet: TMS320C6711.pdf
C6211 Datasheet: C6211 Datasheet: TMS320C6211.pdf
Digital Signal ProcessorDigital Signal ProcessorParametri TecniciParametri Tecnici
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Parameter
I/O bandwidth: Serial Ports (number/speed)
DMA channels
Multiprocessor support
Supply voltage
Power management
On-chip timers (number/width)
Cost
Package
External memory interface controller
JTAG
2 x 75Mbps
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Not inherent
3.3V I/O, 1.8V Core
Yes
2 x 32-bit
US$ 21.54
256 Pin BGA
Yes
Yes
2 x 75Mbps
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Not inherent
3.3V I/O, 1.8V Core
Yes
2 x 32-bit
US$ 21.54
256 Pin BGA
Yes
Yes
TMS320C6211 (@150MHz)
TMS320C6711 (@150MHz)
Digital Signal ProcessorDigital Signal ProcessorParametri TecniciParametri Tecnici
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Can be slower than fixed-point Can be slower than fixed-point counterparts and larger in sizecounterparts and larger in size
Digital Signal ProcessorDigital Signal ProcessorFixed vs. FloatingFixed vs. Floating
FloatingPoint
Ease of Ease of useuse
High High precisionprecisionWide dynamic rangeWide dynamic range
High signal-to-noise ratioHigh signal-to-noise ratio
Higher power Higher power consumptionconsumption
Can be more expensiveCan be more expensive
It is the application that dictates which It is the application that dictates which device and platform to use in order to device and platform to use in order to achieve optimum performance at a low achieve optimum performance at a low
cost cost
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AdvantagesAdvantages
• High throughputHigh throughput• Lower silicon areaLower silicon area• Lower power consumptionLower power consumption• Improved reliabilityImproved reliability• Reduction in system noiseReduction in system noise• Low overall system costLow overall system cost
DisadvantagesDisadvantages
• High investment costHigh investment cost• Less flexibilityLess flexibility• Long time from design to Long time from design to
marketmarket
Digital Signal ProcessorDigital Signal ProcessorGP-DSP vs. ASIC-DSPGP-DSP vs. ASIC-DSP
Application Specific Integrated Circuits Application Specific Integrated Circuits (ASICs) are semiconductors designed (ASICs) are semiconductors designed
for dedicated functionsfor dedicated functions
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VoIP
Digital Signal ProcessorDigital Signal ProcessorTexas Instruments’Texas Instruments’ TMS220 FamilyTMS220 Family
C2000
C5000
C6000
Lowest CostLowest CostControl SystemsControl Systems- Motor Control- Motor Control- Storage- Storage- Digital Ctrl - Digital Ctrl
SystemsSystems
EfficiencyEfficiency Best MIPS per Watt / Best MIPS per Watt /
Dollar / SizeDollar / Size
- Wireless phones- Wireless phones- Internet audio - Internet audio
playersplayers- Digital still cameras - Digital still cameras - Modems- Modems- Telephony- Telephony- VoIP- VoIP
Performance &Performance &Best Ease-of-UseBest Ease-of-Use
- Multi Channel and - Multi Channel and Multi Multi
Function App'sFunction App's- Comm Infrastructure- Comm Infrastructure- Wireless Base-- Wireless Base-
stationsstations- DSL- DSL- Imaging- Imaging- Multi-media Servers- Multi-media Servers- Video- Video
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TMS320TMS320CC64x:64x: The C64x fixed-point DSPs offer the industry's highest level of performance to address the demands of the digital age. At clock rates of up to 1 GHz, C64x DSPs can process information at rates up to 8000 MIPS with costs as low as $19.95. In addition to a high clock rate, C64x DSPs can do more work each cycle with built-in extensions. These extensions include new instructions to accelerate performance in key application areas such as digital communications infrastructure and video and image processing.
TMS320CTMS320C6262x:x: These first-generation fixed-point DSPs represent breakthrough technology that enables new equipments and energizes existing implementations for multi-channel, multi-function applications, such as wireless base stations, remote access servers (RAS), digital subscriber loop (xDSL) systems, personalized home security systems, advanced imaging/biometrics, industrial scanners, precision instrumentation and multi-channel telephony systems.
TMS320CTMS320C6767x:x: For designers of high-precision applications, C67x floating-point DSPs offer the speed, precision, power savings and dynamic range to meet a wide variety of design needs. These dynamic DSPs are the ideal solution for demanding applications like audio, medical imaging, instrumentation and automotive.
Digital Signal ProcessorDigital Signal ProcessorTMS220 - C6000TMS220 - C6000