EE 445S Real-Time Digital
Signal Processing Lab
Fall 2013
Lab #1
Introduction to Hardware & Software
Tools of TMS320C6748 DSK
Outline
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Introduction
C6748 DSK Board
C6748 DSP
C6700 Instruction Set Architecture
DSP/BIOS
Code Composer Studio
winDSK
LabVIEW
MATLAB/MathScript
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Introduction
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Goal is to implement communication system
components by writing C and/or assembly language
programs for the TI TMS320C6748 fixed/floatingpoint DSP.
C6748 DSP resides on the OMAP-L138EVM board
which connects to the PC by USB.
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Fixed vs. Floating Point DSP’s
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Fixed Point DSP’s (Modems, Controllers, Phones…)
 Cheaper and consume less power
 Need special care when programming to avoid overflows
 More dominant in the market
 TMS320C1x, ’C2x, ’C20x, ’C24x (16 bit, for control)
 ’C5x, ’C54x, ’C55x (16 bit, wireless phones and modems)
 ’C62x, ’C64x (16 bit, DSL, imaging, video)
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Floating Point DSP’s (DSL, Video, Imaging…)
 Easier to program,
 Complex architecture (more computationally demanding)
 More expensive.
 ’C3x, ’C4x, ’C67x (32-bit, DSL, imaging, video)
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Advantages of DSP’s vs. Analog Circuit
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Can implement complex linear and non-linear
algorithms,
Application can be modified simply by changing code,
Highly reliable,
Manufacturing is fairly easy.
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OMAP-L138 Functional Block Diagram
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Functional Units
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.M Multiplication Unit:
 16-bit × 16-bit, 32-bit × 32-bit, 64-bit × 64-bit
.L Logic Unit:
 Arithmetic, comparisons and logic operations.
.S Shifter Unit:
 Bit manipulation (set, get, shift, rotate).
.D Data Unit:
 Load/Store to/from memory (exclusively)
 Performs addition and pointer arithmetic.
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DSP Features
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375/456-MHz Fixed/Floating-Point – Load-Store Architecture
with VLIW architecture.
10/100 Mb/s Ethernet MAC (EMAC)
USB2.0 OTG, USB1.1 OHCI interface
Two inter-integrated circuit (I2C) bus interfaces
One multichannel audio serial port (McASP)
Two multichannel buffered serial ports (McBSP) with FIFO
buffers
Two SPI interfaces with multiple chip selects.
Four 64-bit general-purpose timers.
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DSP Features (Contd.)
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Configurable 16-bit host port interface (HPI).
9 banks of 16 pins of general-purpose input/output
(GPIO) with programmable interrupt/event generation
modes.
Three UART interfaces
Asynchronous and SDRAM external memory interface
(EMIFA) for slower memories or peripherals.
A higher speed DDR2/Mobile DDR controller.
A Video Port Interface (VPIF)
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TMS320C6748 Megamodule Block Diagram
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DSP Features (Contd.)
C674x Two Level Cache Memory Architecture
– 32K-Byte L1P Program RAM/Cache
– 32K-Byte L1D Data RAM/Cache
– 256K-Byte L2 Unified Mapped RAM/Cache
– Flexible RAM/Cache Partition (L1 and L2)
 Enhanced Direct-Memory-Access Controller 3 (EDMA3)
– 2 Channel Controllers
– 3 Transfer Controllers
– 64 Independent DMA Channels
– 16 Quick DMA Channels
– Programmable Transfer Burst Size
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C6748 Floating-Point VLIW DSP Core
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Load-Store Architecture With Non-Aligned VLIW
DSP Support
Supports TI’s Basic Secure Boot – 64 General-Purpose
Registers (32 Bit)
Six ALU (32-/40-Bit) Functional Units
• Supports 32-Bit Integer, SP (IEEE Single
Precision/32-Bit) and DP (IEEE Double Precision/64Bit) Floating Point
• Supports up to Four SP Additions Per clock, Four DP
Additions Every 2 clocks.
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C6748 Floating-Point VLIW DSP Core
(Contd.)
Two Multiply Functional Units
 Mixed-Precision IEEE Floating Point Multiply Supported up
to:
– 2 SP x SP → SP Per Clock
– 2 SP x SP → DP Every Two Clocks
– 2 SP x DP → DP Every Three Clocks
– 2 DP x DP → DP Every Four Clocks
 Fixed Point Multiply Supports Two 32 x 32-Bit Multiplies,
Four 16 x 16-Bit Multiplies, or Eight 8 x 8-Bit Multiplies per
Clock Cycle, and Complex Multiples
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DSP/BIOS
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A real-time operating system specific to the
Texas Instruments DSPs.
DSP/BIOS provides a wide range of system
services to an embedded application:
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Preemptive multitasking
Memory management
Real-time analysis.
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DSP/BIOS features
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The scheduler
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Its associated thread classes provide a mechanism for
arranging and controlling the software’s execution.
Periodically
interrupt the
currently
executing thread
Determine what the
highest priority
thread is that is
ready to execute
Start that thread
running
Hardware
timers
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Memory manager
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control the operation of the memory/ cache architecture
and control allocation of memory resources.
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DSP/BIOS features (Contd.)
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Instrumentation
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Communications resources
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provides deterministic, minimally-invasive analysis,
profiling, and statistical functions.
queues, pipes, streams and a device driver mechanism.
Support libraries
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provide standardization of access and hardware
abstraction across multiple DSPs.
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DSP/BIOS Thread Types
HWI
Hardware Interrupts
SWI
Priority
Software Interrupts
TSK
Tasks
IDL
Background
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Implements ‘urgent’ part of real-time event
Hardware interrupt triggers ISRs to run
Priorities set by hardware
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Performs HWI ‘follow-up’ activity
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‘posted’ by software
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PRDs (periodic functions) are prioritized as SWIs
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14 priority levels
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Runs programs concurrently under separate contexts
Usually enabled to run by posting a ‘semaphore’
(a task signaling mechanism)
15 priority levels
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Multiple IDL functions
Runs as an infinite loop (like traditional while loop)
Single priority level
Code Composer Studio
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CCS is TI’s proprietary IDE that provides a transition
between a high-level DSP program and an on-board
machine language program. It is used to:
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Generate programs for the C6748 DSP using C language,
Load them into the DSK,
Run them,
Monitor program execution.
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winDSK
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A windows-based DSP demonstration program
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No need of other software.
Direct communication with DSP board through serial port
Demonstration of all the projects are available.
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LabVIEW
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Laboratory Virtual Instrumentation Engineering Workbench.
It is a powerful IDE for data acquisition,
instrumentation, analysis, signal processing, control…
LabVIEW programs called Virtual Instruments (VI’s).
Each VI has 2 components:
 Front Panel: user interface of the VI, has all controls
and indicators for I/O.
 Block Diagram: code is added using graphical
representations of functions to control front panel
objects.
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LabVIEW
Front Panel
Block Diagram
Online LabView Interactive Tutorial can be found at:
http://www.ni.com/gettingstarted/labviewbasics/
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MATLAB
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MATrix LABoratory.
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It is a numerical computing environment and
programming language.
Allows easy matrix manipulation, plotting of functions
and data, implementation of algorithms, creation of
GUI’s…
Includes many specialized toolboxes that extend the
regular MATLAB environment (communications,
Control, Signal Processing…).
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MATLAB
Command Window
Workspace
Current Directory
Command History
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MATLAB
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MATLAB Help is very practical and user-friendly.
Can access the MATLAB Help by pressing F1, or going to
“Help → MATLAB Help”.
Also, in the Command Window, can type
 help <function_name> to show the help document of a given
function.
 lookfor <keyword> to searche all help documents for a given
keyword.
MATLAB Tutorial can be found at
http://www.mathworks.com/academia/student_center/tutorial
s/
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MathScript
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Software from LabVIEW.
Same syntax as MATLAB but does not support all functions
available in MATLAB.
Appendix D in course reader
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http://zone.ni.com/devzone/cda/tut/p/id/3502
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…The End!
See You Next Week!
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