Mid Semester Presentation - High Speed Digital Systems Laboratory
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Transcript Mid Semester Presentation - High Speed Digital Systems Laboratory
Technion - Israel institute of technology
department of Electrical Engineering
High speed digital systems laboratory
מכון טכנולוגי לישראל- הטכניון
הפקולטה להנדסת חשמל
מעבדה למערכות ספרתיות מהירות
Midterm Presentation
Transfer fax over IP
in cellular networks
Performed by: Carmel Yuval, Mishael Avihoo
Instructor: Orbach Mony
Cooperated with: Qualcomm Israel
High speed digital systems laboratory
המעבדה למערכות ספרתיות מהירות
Project Goal
Transmit fax page from a fax machine to
a computer and receive a fax page from a
computer to a fax machine.
המעבדה למערכות ספרתיות מהירות
High speed digital systems laboratory
Block Diagram
Control/
feedback
Fax
SLIC
DSP
Computer
High speed digital systems laboratory
המעבדה למערכות ספרתיות מהירות
Functional Description
• Converting analog fax transmission to a digital signal
• Decoding and interpreting the digital signal
• Determine the fax call state from the digital signal using state
machine, negotiating accordingly with the computer
• Transmitting an image information to the computer using ATCommands
• Repeating the process for the case of the computer initiating
the fax call
המעבדה למערכות ספרתיות מהירות
High speed digital systems laboratory
Interfaces
SCLK
CS
SDI
SDO
ProSLIC
SCLK0
DRX
PCM
DT0
DTX
PCM
DR0
FSYNC
Parallel Interface
ADSP-2181
RFS0
EZ-ICE
Evaluating
Board
DT1
CONTROL
PC
DR1
EZ-KIT
LOCAL
FAX
Analog
PCLK
RS-232
PC
EMULATE
IWF
High speed digital systems laboratory
המעבדה למערכות ספרתיות מהירות
Interfaces (cont.)
• ProSLIC
• Parallel port – to controller (computer).
• Analog – to phone line (200-2200Hz).
• Serial – PCM digital signal to DSP (2.048MHz).
• DSP
• Serial RS-232 – to PC emulating IWF (4800-19200bps).
• EZ-ICE – for debugging DSP (9600bps).
• Serial – PCM digital signal to ProSLIC (2.048MHz).
המעבדה למערכות ספרתיות מהירות
High speed digital systems laboratory
Data Rates and Bandwidths
Place
Rate / Frequency
Input (Phone Line)
200-2200Hz
Output (RS-232)
4800 - 19200bps
PCM interface
2.048MHz
DSP clock
20MHz
PCM Sampling Rate 8KHz
High speed digital systems laboratory
המעבדה למערכות ספרתיות מהירות
Built In Tests
• Program debugging
• Using VisualDSP+EZ-ICE.
• Log points – TBD.
•ProSLIC
• Power on – Power LEDs.
• Computer interface – Using program.
• Phone line interface – Tone generation, using fax.
• PCM interface – TBD.
High speed digital systems laboratory
המעבדה למערכות ספרתיות מהירות
Built In Tests (cont.)
• DSP
• Power on – Power LEDs.
• Computer interface – TBD.
• PCM interface - TBD.
• EZ-ICE interface – TBD.
המעבדה למערכות ספרתיות מהירות
High speed digital systems laboratory
Complete System Overview
PSTN
IWF
MSC
FAX
BSC
BTS
MS
HOST DSP
FAX
High speed digital systems laboratory
המעבדה למערכות ספרתיות מהירות
Complete System Overview (cont.)
• MS – Mobile Station - Wireless communication device,
contains the DSP, interfaces the fax to the cellular network.
• BTS – Base Transceiver Station – Connects the MS to the
cellular network using wireless interface.
• BSC – Base Station Controller – Controls Resources.
High speed digital systems laboratory
המעבדה למערכות ספרתיות מהירות
Complete System Overview (cont.)
• MSC – Mobile Switching Center – The cellular network
PSTN.
• IWF – Inter Working Function – Connects the cellular
network to PSTN using modems (Dial up, fax, etc.).
• PSTN – Public Switching Telephone Network – connects
subscribers.
High speed digital systems laboratory
המעבדה למערכות ספרתיות מהירות
Project’s Alternatives
• External Modem – Of the shelf solution, cheap, but large, can
not generate PSTN functions.
• Canceling Vocoder (voice compression algorithm) – Not
supported.
המעבדה למערכות ספרתיות מהירות
High speed digital systems laboratory
ProSLIC
• Provides a complete analog telephone interface.
• “Subscriber Line Interface Circuit”.
• codec.
• DTMF functions.
• Signal generation functions (linefeed).
• Consist A/D, D/A, DC to DC converter, programmable signal
generator, signal detector and much more on one chip.
High speed digital systems laboratory
המעבדה למערכות ספרתיות מהירות
ProSLIC (cont.)
• codec (coder decoder):
• Convert analog signal to PCM.
• Convert PCM to analog signal.
• Comply with A-Law, μ-Law.
High speed digital systems laboratory
המעבדה למערכות ספרתיות מהירות
ProSLIC (cont.)
• DTMF functions:
• “Dual Tone Multi Frequency”.
• Two frequency generators for generating DTMF signals.
• DTMF detection.
High speed digital systems laboratory
המעבדה למערכות ספרתיות מהירות
ProSLIC (cont.)
• Linefeed:
• on-hook voltage.
• off-hook loop current.
• on-hook transmission ringing voltage.
High speed digital systems laboratory
המעבדה למערכות ספרתיות מהירות
DSP Software
• The project consist of written program which works with a
host processor.
• The written software will be alternated in order to disable the
host interface.
High speed digital systems laboratory
המעבדה למערכות ספרתיות מהירות
DSP Software (cont.)
Interrupts
IWF
DSP
HOST
DPR
(SM)
High speed digital systems laboratory
המעבדה למערכות ספרתיות מהירות
DSP Software (cont.)
• The host and the DSP shares RAM for exchange commands
and data.
• When the host or the DSP puts new data at the shared
memory, they initiates interrupt to inform the other side about
the new data.
High speed digital systems laboratory
המעבדה למערכות ספרתיות מהירות
DSP Software (cont.)
DSP
DPR
(SM)
PC
Interrupts
Host
Module
המעבדה למערכות ספרתיות מהירות
High speed digital systems laboratory
DSP Software (cont.)
• The host module is a software function in the DSP.
• The host module will connect the DSP to the PC (IWF) via
RS-232 (SPORT1).
• The module will acts as the host when reading and writing
into the shared memory.
• The module will initiate interrupts to the DSP and respond to
such.
DSP
DPR
(SM)
PC
Interrupts
Host
Module
High speed digital systems laboratory
המעבדה למערכות ספרתיות מהירות
Timetable
Week
Duty (Avihoo)
Duty (Yuval)
28/12 – 1/1
EZ-ICE Setup
11-15/1
DSP Integration
(Software)
Old Program
Integration
Writing Module
18-22/1
Writing Module
ProSLIC issues
25-29/1
Writing Module
Interrupt handling
4-8/1
Hardware
Integration
PC Interface