INTRODUCTION TO Microprocessors

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INTRODUCTION TOMicroprocessors

• Dr. Hugh Blanton
• ENTC 4337/5337

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Objectives

• Build intuition for signal processing concepts
• Translate signal processing concepts into
  real-time digital communications software in
  laboratory

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General Information

• Contact Information
• Emailblanton_at_etsu.edu
• Phone[phone]
• Web Page
• http//faculty.etsu.edu/blanton
• Office Hours
• MWF1015-1145

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Grading

• Calculation of numeric grades
• 15 midterm 1
• 25 final 2 (semi-cumulative)
• 20 homework
• 50 laboratory

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• Laboratory component
• Students work in teams of two on lab
  assignments/reports
• Assign team members same lab report grade and
  then apply individual deductions for
  attendance/participation
• Lowest lab report dropped

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Academic Integrity

• Homework/Exam assignments
• Discuss homework/exam questions with others
• Be sure to submit your own independent solution
• Turning in two identical (or nearly identical)
  homework sets is considered academic dishonesty

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• Laboratory reports
• Should only contain work of those named on report
• If any other work is included, then reference
  source
• Copying information from another source without
  giving proper reference and quotation is
  plagiarism
• Source code must be original work

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Topics

• The TMS320C6X (1 week)
• Programming (4 weeks)
• C
• Code Composer
• Assembly Language
• Hardware (4 weeks)
• architecture

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• Applications
• FIR Filters
• IIR Filters
• Fast Fourier Transforms

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TMS320C6x Manuals

• You need to refer to various TMS320C6000 manuals,
  which are only available electronically
• Code Composer Users Guide
• http//focus.ti.com/lit/ug/spru301c/spru301c.pdf
• Optimizing C Compiler
• http//www-s.ti.com/sc/psheets/spru187k/spru187k.p
  df
• Programmers Guide
• http//www-s.ti.com/sc/psheets/spru198g/spru198g.p
  df
• CPU and Instruction Set Reference Guide
• http//www-s.ti.com/sc/psheets/spru189f/spru189f.p
  df

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Microprocessors

• General-purpose processors or microcontrollers
  (GPPs/MCUs for short) are either
• not specialized for a specific kind of
  applications (in the case of general-purpose
  processors), or
• they are designed for control-oriented
  applications (in the case of microcontrollers).

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Digital Signal Processors

• DSP processors have features designed to support
  high-performance, repetitive, numerically
  intensive tasks.
• Mostly designed with the same few basic
  operations in mind
• They share the same set of basic characteristics
• These characteristics fall into three categories
• specialized high speed arithmetic
• data transfer to and from the real world
• multiple access memory architecture

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DSP Features

• Features that accelerate performance in DSP
  applications include
• Single-cycle multiply-accumulate (MAC)
  capability
• high-performance DSPs often have two multipliers
  that enable two multiply-accumulate operations
  per instruction cycle
• some DSP have four or more multipliers
• Specialized addressing modes, for example,
• pre- and post-modification of address pointers,
• circular addressing, and
• bit-reversed addressing

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DSP Features

• Most DSPs provide various configurations of
  on-chip memory and peripherals tailored for DSP
  applications.
• DSPs generally feature multiple-access memory
  architectures that enable DSPs to complete
  several accesses to memory in a single
  instruction cycle
• Specialized execution control.
• Usually, DSP processors provide a loop
  instruction that allows tight loops to be
  repeated without spending any instruction cycles
• for updating and testing the loop counter or
• for jumping back to the top of the loop

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DSP Features

• DSP processors are known for their irregular
  instruction sets, which generally allow several
  operations to be encoded in a single instruction.
  
• For example, a processor that uses 32-bit
  instructions may encode
• two additions,
• two multiplications, and
• four 16-bit data moves into a single instruction.
  
• In general, DSP processor instruction sets allow
  a data move to be performed in parallel with an
  arithmetic operation.
• GPPs/MCUs, in contrast, usually specify a single
  operation per instruction

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DSP Features

• It is worth noting that the difference between
  DSPs and GPPs/MCUs is fading
• many GPPs/MCUs now include DSP features, and DSPs
  are increasingly adding microcontroller features.

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What is a DSP?

• Digital Signal Processors (DSP) process digital
  signals
• An alternative method to process analog world
  signals
• Once the signal is in digital form, the DSP can
  easily process it
• After the DSP has processed the signal, the
  output signal must be converted back to analog so
  that we can sense it.

ADC
DSP
DAC
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Why DSP?

• Advantages of digital signal processing
• Programmabilityone hardware does many tasks
• Flexibility and upgradeabilitydevelop a new code
• RepeatabilityA CD player always plays the same
  music quality
• Advantages of analog signal processing
• low cost in some applicationsattenuators,
  amplifiers
• wide bandwidth (GHz)
• Infinite resolution (no quantization error) and
  low signal levels

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The DSP System

• DSP chip
• Arithmetic Logic Unit (ALU)
• TMS320C6X
• Memory
• Converters
• Analog-to-Digital
• Digital-to-Analog
• Communication Ports
• Serial
• Parallel

Memory
DSP
ADC
DAC
Ports
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Review Signals

• Continuous-time (analog) signals are functions of
  a real argument
• x(t) where t can take any real value
• Discrete-time (digital) signals are functions of
  an argument that takes values from a discrete set
  xn
• n? ...-3,-2,-1,0,1,2,3...
• Integer index n instead of time t for
  discrete-time systems
• Value for x may be real or complex

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Analog and Digital Signals

• Amplitude of an analog signal can take any real
  or complex value at each time (sample)
• Amplitude of a digital signal takes values from a
  discrete set

1
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Analog and Digital Signals

• A system is a transformation from one signal
  (called the input) to another signal (called the
  output or the response).
• Continuous-time systems with input signal x and
  output signal y (a.k.a., the response)
• Discrete-time system examples

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Audio Compact Discs

• Human hearing is from about 20 Hz to 20 kHz
• Sampling theorem sample analog signal at a rate
  of more than twice the highest analog frequency
• Apply a lowpass filter to pass frequencies up to
  20 kHz
• e.g. a coffee filter water (small particles)
  through a coffee filter but not coffee grounds
  (large particles)
• Lowpass filter needs 10 of maximum passband
  frequency to roll off to zero (2 kHz rolloff in
  this case).
• Sampling at 44.1 kHz captures analog frequencies
  that are less than 22.05 kHz

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Signal Processing Systems

• Speech synthesis and speech recognition
• Audio CD players
• Audio compression (MP3, AC3)
• Image compression (JPEG, JPEG 2000)
• Optical character recognition
• Video CDs (MPEG 1)
• DVD, digital cable, and HDTV (MPEG 2)
• Wireless video (MPEG 4/H.263)

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Communication Systems

• Voiceband Dialup/Fax modems
• Digital subscriber line (DSL) modems
• ISDN 144 kilobits per second (kbps)
• Business/symmetric HDSL and HDSL2
• Home/symmetric ADSL and VDSL
• Cable modems
• Cell phones
• First generation (1G) AMPS
• Second generation (2G) GSM, IS-95 (CDMA)
• Third generation (3G) cdma2000, WCDMA

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DSP Architectures

• Multiply-Add-Accumulate (MAC) instruction
• Most common operation in DSP,
• ABCD
• Typically 70 clock cycles with ordinary
  processors
• Single instruction cycle
• Havard architecture
• Separate data memory/bus and program memory/bus
• Multiple memory accesses per instruction cycle
• Modified von Neuman architecture
• multiple memory accesses per instruction cycle by
  the simple trick of running the memory clock
  faster than the instruction cycle.

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DSP Architectures

• Deterministic interrupt service routine latency
• Special addressing modes supported in hardware
• Modulo addressing for circular buffers (e.g. FIR
  filters)
• Bit-reversed addressing (e.g. fast Fourier
  transforms)
• DSP needs a program that is a series of
  instructions that perform certain functions.

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Digital vs Analog
Digital Signal Processing
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Impact of DSP on Modern Living
Cellular/mobile telephony Speech and channel
coding Voice and data processing Power
management Multipath equaliztion
Digital audio Stereo and surround
sound Audio equalization and mixing
Electronic music
Medical electronics Critical/intensive care
monitors Digital X-rays
ECG analyzers
Cardiac monitors
Medical imaging
Automotive Digital Audio
Digital Radio
Personal communication systems
Active suspension
Personal computer Sound cards
Data storage and retrieval Error
correction/concealment Multimedia
Modems
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Analog digital signals
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DSP aim tools