Digital Signal Processor

Digital Signal Processor (DSP)– Similar to a Microprocessor(µP), e.g. core of a computing

system

– Additional Hardware Units to speed up computing of sophisticated mathematical operations:

• Additional Hardware Multiply Unit(s)

• Additional Pointer Arithmetic Unit(s)

• Additional Bus Systems for parallel access

• Additional Hardware Shifter for scaling and/or multiply/divide by 2n

Digital Signal Controller (DSC)

Digital Signal Controller (DSC)– recall: a Microcontroller(µC) is a single chip Microcomputer

with a Microprocessor(µP) as core unit.

– Now: a Digital Signal Controller(DSC) is a single chip Microcomputer with a Digital Signal Processor(DSP) as core unit.

– By combining the computing power of a DSP with memory and peripherals in one single device we derive the most effective solution for embedded real time control solutions that require lots of math operations.

– DSC –Example: Texas Instruments C2000 family.

C2000

C5000

C6000

Efficient Integration

for Control

DSC

Power Efficient

Performance

DSP

High Performance

‘C’ Efficiency

DSP

Texas Instruments DSP/DSC -

Portfolio

TMS320 –FamilyBranches

Different families and sub-families

exist to support different markets

Lowest Cost

Control Systems

Motor Control

Storage

Digital Ctrl Systems

C2000 C5000

Efficiency

Best MIPS per

Watt / Dollar / Size

Wireless phones

Internet audio players

Digital still cameras

Modems

Telephony

VoIP

C6000

Multi Channel and

Multi Function App's

Comm Infrastructure

Wireless Base-stations

DSL

Imaging

Multi-media Servers

Video

Performance &Best Ease-of-Use

DC Motors Features

Electrical sparks due to commutators

Produce significant EMI!

NOT suitable for deployment in combustible environments

Limited speed due to commutators

Mechanical noise due to commutators

Commutators limit life time

-

Internal commutation

Speed proportionate to voltage applied

Easy to control: ON/OFF, Proportional

Low Cost

+

DC motors control requirements

• Input

– Torque, speed, direction, position

• Control

– Simple PWM scheme, ON/OFF approach

• Feedback

– Encoder for speed or direction feedback

• Driver

– Low-side Switch (MOSFET) for uni-directional type

– H-Bridge for bi-directional type

DC Motor

s s

sETachometer sKsV t

tK

s

sV

sE ―Control Voltage

―Tachometer Measure (V)

―DC Motor Angular Speed

―Tachometer Constant

m

mK ―Motor Torque Constant

―Motor Time Constant

sEs

Ksm

m1

1

tm

m

m

m

K

sE

s

sK

sE

s

1

1

te MSpeed Reference

Speed Measure

(Tachometer)

+

-Speed

Controller

Control Voltage Motor

Speed

The DC Motor Control Loop

Speed Reference

+

-

Digital to Analog

Converter

Speed Control

ToMotor

Measured Speed (From Tachometer)

The Speed controller comprises two blocks •Speed Control:

•Digital to Analog converter:

The Speed Controller

DAC

PWM LPF

•Digital to Analog converter:

This block is implemented using a PWM signal generator and a Low Pass Filter

M

Speed Measure

(Tachometer)

Amplifier

DC Motor Kit

Stroboscope

RPM

TMS320F2812

LPF AmplifierPWM1

Voltmeter

Connecting the eZdsp to your PC

25 pin maleD-sub connector(Plugs into parallelport on PC)

25 Conductor Cable

25 pin maleD-sub connector

25 pin femaleD-sub connector

To wall outlet

PowerSupply

PowerConnector (P6)+5V

I/O Interface (P4/P8/P7)

TMS320F2812 - DSP ANALOGInterface (P5/P9)

Parallel Port/JTAGControllerInterface (P3)

JTAG Interface (P1) EXPANSIONData & Address (P2) SRAM

64K x 16

Broad C28x™ Application Base

Digital Power Supply

Provides control, sensing,

PFC, and other functions

Printer

Print head control

Paper path motor control

Evaluating Other Segments e.g.. Musical Instruments

Non-traditional

Motor Control

Many new cool

applications to

come

Optical Networking

Control of laser diode

tm

m

m

m

K

sE

s

sK

sE

s

1

1

te MSpeed Reference

Speed Measure

(Tachometer)

+

-Speed

Controller

Control Voltage Motor

Speed

The DC Motor Control Loop

MT150F

I/F Circuit

eZDSPF

M

Tacho

Servo Amplifier

SA150D

PWM1

ADCINA0

DC Motor Kit

Power Supply

PS 150E

RTDX

ADCINA0

Interface Circuit

TMS320F2812

M

Speed Measure

(Tachometer)

AmplifierPWM1

Attenuator

ADCINA0

LPF

DC Motor Kit

Amplifier

0-3 V

(Digital)

0-3 V

(Analog)

0 to 15 V (Analog)

-15 V to 0 (Analog)

Signal Types and Voltage Levels

LPF Amplifier Circuit

Inverting Amplifier with LPF

DC Motor

s s

sETachometer sKsV t

tK

s

sV

sE ―Control Voltage

―Tachometer Measure (V)

―DC Motor Angular Speed

―Tachometer Constant

m

mK ―Motor Torque Constant

―Motor Time Constant

sEs

Ksm

m1

1

DATA ACQUISITION CARD

NI LabviewProfessional

-1

0

1

2

3

4

5

6

7

0 0.5 1 1.5 2 2.5

Sp

ee

d

Time

Time Constant

Connecting the eZdsp to your PC

25 pin maleD-sub connector(Plugs into parallelport on PC)

25 Conductor Cable

25 pin maleD-sub connector

25 pin femaleD-sub connector

To wall outlet

PowerSupply

Fig. 8.4 Pulses for 10% & 25% Duty Ratio

Fig. 8.5 Pulses for 50% & 75% Duty Ratio

Presented by:

M.Pratyusha

G.Hema Manvi

Ch.Sravana Vindhya

Guidance:

Mr.M.Chakravarthy

Thank You