Tektronix TDSDDM1 User Manual
User Manual
TDSDDM1
Disk Drive Measurement Application
071-0174-02
This document supports software version 1.0.26
and above.
Copyright © T ektronix, Inc. All rights reserved. Licensed software products are owned by Tektronix or its suppliers and
are protected by United States copyright laws and international treaty provisions.
Use, duplication, or disclosure by the Government is subject to restrictions as set forth in subparagraph (c)(1)(ii) of the
Rights in T echnical Data and Computer Software clause at DFARS 252.227-7013, or subparagraphs (c)(1) and (2) of the
Commercial Computer Software – Restricted Rights clause at F AR 52.227-19, as applicable.
T ektronix products are covered by U.S. and foreign patents, issued and pending. Information in this publication supercedes
that in all previously published material. Specifications and price change privileges reserved.
Printed in the U.S.A.
T ektronix, Inc., P.O. Box 1000, Wilsonville, OR 97070–1000
TEKTRONIX and TEK are registered trademarks of T ektronix, Inc.
WARRANTY
T ektronix warrants that the media on which this software product is furnished and the encoding of the programs on the
media will be free from defects in materials and workmanship for a period of three (3) months from the date of shipment.
If a medium or encoding proves defective during the warranty period, T ektronix will provide a replacement in exchange
for the defective medium. Except as to the media on which this software product is furnished, this software product is
provided “as is” without warranty of any kind, either express or implied. T ektronix does not warrant that the functions
contained in this software product will meet Customer’s requirements or that the operation of the programs will be
uninterrupted or error-free.
In order to obtain service under this warranty, Customer must notify Tektronix of the defect before the expiration of the
warranty period. If T ektronix is unable to provide a replacement that is free from defects in materials and workmanship
within a reasonable time thereafter, Customer may terminate the license for this software product and return this software
product and any associated materials for credit or refund.
THIS WARRANTY IS GIVEN BY TEKTRONIX IN LIEU OF ANY OTHER WARRANTIES, EXPRESS OR
IMPLIED. TEKTRONIX AND ITS VENDORS DISCLAIM ANY IMPLIED WARRANTIES OF
MERCHANTABILITY OR FITNESS FOR A PAR TICULAR PURPOSE. TEKTRONIX’ RESPONSIBILITY TO
REPLACE DEFECTIVE MEDIA OR REFUND CUSTOMER’S PAYMENT IS THE SOLE AND EXCLUSIVE
REMEDY PROVIDED TO THE CUSTOMER FOR BREACH OF THIS WARRANTY. TEKTRONIX AND ITS
VENDORS WILL NOT BE LIABLE FOR ANY INDIRECT , SPECIAL, INCIDENTAL, OR CONSEQUENTIAL
DAMAGES IRRESPECTIVE OF WHETHER TEKTRONIX OR THE VENDOR HAS ADVANCE NOTICE OF
THE POSSIBILITY OF SUCH DAMAGES.
Table of Contents
Getting Started
Preface vii. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Related Documentation vii. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Conventions vii. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Contacting T ektronix viii. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Product Description 1–1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Compatibility 1–1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Requirements and Restrictions 1–2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Updates 1–2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Accessories 1–2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Installation 1–3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Installing the Application 1–3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Updates Through a Web Browser 1–4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Disk Drive Connection 1–4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Configuration 1–7. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Setting Up the Oscilloscope Trigger 1–7. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Setting Up the Application Trigger 1–8. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Hysteresis 1–9. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Configuring the Input Channels 1–11. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Operating Basics
Reference
Functional Overview 2–1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Starting the Application 2–1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Leaving the Application 2–3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Starting the Measurement 2–4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Viewing the Waveform 2–6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Using the Local Help 2–6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Tutorial 2–7. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Preparation 2–7. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Example 1: Measuring the Track Average Amplitude 2–7. . . . . . . . . . . . . . . . . . . . .
Example 2: Measuring the Pulse Width at 50% 2–8. . . . . . . . . . . . . . . . . . . . . . . . . .
Example 3: Creating and Viewing Track Profiles 2–10. . . . . . . . . . . . . . . . . . . . . . . .
Example 4: Saving a Setup and Exiting the Application 2–11. . . . . . . . . . . . . . . . . . .
Example 5: Recalling a Setup 2–12. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Menu Structure 3–1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Menu Summary 3–1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Menu Structure 3–3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
TDSDDM1 Disk Drive Measurement Application User Manual
i
Table of Contents
Setup Parameters 3–5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Saving and Recalling Setups 3–5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Measuring Over a Range of Sectors 3–6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Cursor Gating 3–7. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Localizing Measurements: an Alternate Method 3–9. . . . . . . . . . . . . . . . . . . . . . . . .
Adding Pass/Fail Results to Measurement Data 3–9. . . . . . . . . . . . . . . . . . . . . . . . .
Measurement Descriptions 3–11. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Measurement Features 3–11. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
W arning Messages 3–12. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Track Average Amplitude, TAA 3–13. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Track Average Amplitude (Plus), TAA+
Track Average Amplitude (Minus), TAA– 3–16. . . . . . . . . . . . . . . . . . . . . . . . .
Pulse Width at 50%, PW50 3–18. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
50% Pulse Width (Positive), PW50+
50% Pulse Width (Negative), PW50– 3–21. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Nonlinear Transition Shift, NLTS 3–23. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Signal-to-Noise Ratio, SNR 3–30. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Overwrite 3–34. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Resolution 3–36. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Asperity 3–39. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Snapshot Measurements 3–41. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Snapshot Measurement Definitions 3–41. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Track Profiles 3–45. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Using Track Profiles 3–46. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
About the Track Profile Reference Memory 3–48. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Appendices
Index
Appendix A: Specifications A–1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
ii
TDSDDM1 Disk Drive Measurement Application User Manual
List of Figures
Table of Contents
Figure 1–1: TDSDDM1 Disk Drive Measurement Application 1–1. . . . .
Figure 1–2: Primary setup connections 1–5. . . . . . . . . . . . . . . . . . . . . . . . .
Figure 1–3: Secondary setup connections 1–6. . . . . . . . . . . . . . . . . . . . . . .
Figure 1–4: Selecting the sectors to measure 1–9. . . . . . . . . . . . . . . . . . . .
Figure 1–5: Using hysteresis to avoid false identification of peaks 1–10. . .
Figure 1–6: Hysteresis menu 1–11. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Figure 1–7: The Input Channels menu 1–12. . . . . . . . . . . . . . . . . . . . . . . . .
Figure 2–1: Starting the application 2–2. . . . . . . . . . . . . . . . . . . . . . . . . . .
Figure 2–2: Disk Drive Measurement Application initial display 2–3. . .
Figure 2–3: Returning to the application 2–3. . . . . . . . . . . . . . . . . . . . . . .
Figure 2–4: Selecting a measurement from the Measure menu 2–4. . . . .
Figure 2–5: The Control menu 2–5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Figure 2–6: Track average amplitude (TAA) measurement 2–8. . . . . . . .
Figure 2–7: Pulse width at 50% (PW50) measurement with cursor
gating 2–9. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Figure 2–8: Track profile measurement 2–11. . . . . . . . . . . . . . . . . . . . . . . .
Figure 3–1: Selecting menus 3–1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Figure 3–2: Save Setup and Recall Setup selections in the Utility
menu 3–6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Figure 3–3: Selecting the sectors to measure 3–7. . . . . . . . . . . . . . . . . . . .
Figure 3–4: Localizing a measurement using cursor gating 3–8. . . . . . . .
Figure 3–5: Limit Test results 3–9. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Figure 3–6: Setting pass/fail limits 3–10. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Figure 3–7: Standard measurement, snapshot measurement, and
track profile 3–11. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Figure 3–8: Track average amplitude measurement 3–13. . . . . . . . . . . . . .
Figure 3–9: TAA measurement 3–15. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Figure 3–10: TAA– measurement 3–16. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Figure 3–11: TAA+ and TAA– measurements 3–17. . . . . . . . . . . . . . . . . . .
Figure 3–12: PW50 measurement 3–18. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Figure 3–13: Parameters for PW50 disk drive measurements 3–20. . . . . .
Figure 3–14: PW50+ measurement 3–21. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Figure 3–15: Parameters for PW50+ and PW50– disk drive
measurements 3–22. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
TDSDDM1 Disk Drive Measurement Application User Manual
iii
Table of Contents
Figure 3–16: NLTS measurement 3–24. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Figure 3–17: Selecting an NLTS measurement 3–26. . . . . . . . . . . . . . . . . . .
Figure 3–18: Specifying the NLTS polynomial 3–28. . . . . . . . . . . . . . . . . . .
Figure 3–19: SNR measurement 3–30. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Figure 3–20: Specifying the SNR parameters 3–31. . . . . . . . . . . . . . . . . . . .
Figure 3–21: Overwrite measurement 3–34. . . . . . . . . . . . . . . . . . . . . . . . . .
Figure 3–22: Resolution measurement 3–36. . . . . . . . . . . . . . . . . . . . . . . . .
Figure 3–23: Asperity measurement 3–39. . . . . . . . . . . . . . . . . . . . . . . . . . .
Figure 3–24: Snapshot measurement data 3–41. . . . . . . . . . . . . . . . . . . . . .
Figure 3–25: Time PT and Time TP measurements 3–43. . . . . . . . . . . . . .
Figure 3–26: Track profile waveform 3–45. . . . . . . . . . . . . . . . . . . . . . . . . .
Figure 3–27: Specifying the track profile parameters 3–47. . . . . . . . . . . . .
Figure 3–28: Track profile reference memory 3–48. . . . . . . . . . . . . . . . . . .
iv
TDSDDM1 Disk Drive Measurement Application User Manual
List of Tables
Table of Contents
Table 1–1: Primary setup channel assignments 1–5. . . . . . . . . . . . . . . . . .
Table 1–2: Default input channel assignments 1–11. . . . . . . . . . . . . . . . . .
Table A–1: TDSDDM1 Disk Drive Measurement Application
measurements A–1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
TDSDDM1 Disk Drive Measurement Application User Manual
v
Table of Contents
vi
TDSDDM1 Disk Drive Measurement Application User Manual
Preface
Related Documentation
This manual contains operating information for the TDSDDM1 Disk Drive
Measurement Application. The manual consists of the following chapters:
H The chapter Getting Started briefly describes the TDSDDM1 Disk Drive
Measurement Application and provides installation instructions.
H The chapter Operating Basics covers basic operating principles of the
application.
H The chapter Reference describes how to perform specific tasks.
H The Appendices provide a list of specifications.
The following documents are related to the use of this product:
H The TDS 500D, TDS 600B, & TDS 700D Digitizing Oscilloscope User
Manual (Tektronix part number 071-0130-XX) provides operating instruc-
tions for general oscilloscope features.
Conventions
H The International Disk Drive Equipment and Materials Association
(IDEMA) 1995 Standards Binder, section T for Test Methods, is the source
document for test criteria used by the TDSDDM1 Disk Drive Measurement
Application.
This manual uses the following conventions:
H For brevity, this manual generally refers to the TDSDDM1 Disk Drive
Measurement Application as the Disk Drive Measurement Application or
simply as the application.
H When steps require that you make a sequence of selections using front panel
controls and menu buttons, an arrow ( ➞
front panel button and a menu, or between menus. Also, whether a name is a
main menu or side menu item is clearly indicated: Press VERTICAL
MENU ➞ Coupling (main) ➞ DC (side) ➞ Bandwidth (main) ➞ 250 MHz
(side).
) marks each transition between a
TDSDDM1 Disk Drive Measurement Application User Manual
vii
Preface
Contacting Tektronix
Product
Support
Service
Support
For other
information
To write us Tektronix, Inc.
For application-oriented questions about a Tektronix measurement product, call toll free in North America:
1-800-TEK-WIDE (1-800-835-9433 ext. 2400)
6:00 a.m. – 5:00 p.m. Pacific time
Or contact us by e-mail:
tm_app_supp@tek.com
For product support outside of North America, contact your
local Tektronix distributor or sales office.
Contact your local Tektronix distributor or sales office. Or visit
our web site for a listing of worldwide service locations.
http://www.tek.com
In North America:
1-800-TEK-WIDE (1-800-835-9433)
An operator will direct your call.
P.O. Box 1000
Wilsonville, OR 97070-1000
viii
TDSDDM1 Disk Drive Measurement Application User Manual
Getting Started
Product Description
The TDSDDM1 Disk Drive Measurement Application is a software package that
adds disk drive measurement and analysis capability to a Tektronix oscilloscope.
With this application you can quickly and easily set up, acquire, and analyze
signals from your disk drives, in accordance with IDEMA (International Disk
Drive Equipment and Materials Association) standards.
Compatibility
Figure 1–1: TDSDDM1 Disk Drive Measurement Application
The Disk Drive Measurement Application is compatible with the following
Tektronix oscilloscopes:
H All TDS 500D and 700D Digital Phosphor Oscilloscopes with Option HD
(hard disk drive) or Option 2M (hard disk drive plus 8 MB record length)
H TDS 600C Digitizing Oscilloscopes with an Option HD (hard disk drive)
H TDS 700C Color Digitizing Oscilloscopes serial number B020100 and up,
with Option HD (hard disk drive) or Option 2M (hard disk drive plus 8 MB
record length), and with firmware version 5.2e and up
For a current list of compatible oscilloscopes, check the Tektronix, Inc. web site,
http://www.tektronix.com/Measurement/scopes/index.html
Drivers category.
in the Software and
TDSDDM1 Disk Drive Measurement Application User Manual
1–1
Product Description
Requirements and Restrictions
The TDS Run-Time Environment V1.1 software or above must be installed on
the oscilloscope to operate the Disk Drive Measurement Application.
The application does not support control by external GPIB commands.
Updates
You can find information about this and other applications at the Tektronix, Inc.
web site, http://www.tektronix.com/Measurement/scopes/index.html
Software and Drivers category. Check this site for application updates that you
can download and for free applications.
For instructions, see Updates Through a Web Browser on page 1–4.
Accessories
in the
There are no standard accessories for this product.
The P6246 and P6247 Differential Probes are recommended for connecting to
Read channel signals.
1–2
TDSDDM1 Disk Drive Measurement Application User Manual
Installation
This application resides on a floppy disk. You can download updates, if any,
from the Tektronix ftp site through a web browser.
NOTE. To operate the Disk Drive Measurement Application, the TDS Run-Time
Environment V1.1 or above must be installed on your oscilloscope.
Installing the Application
To install the application from the floppy disk to your oscilloscope, follow these
steps:
1. Create a backup copy of the floppy disks. You can now store the original
NOTE. Additional information about the product or installation, if any, is located
in a Readme.txt file on the floppy disk. You should insert the floppy disk into a
DOS-based personal computer and read the file before you continue.
disks and work from the backup copies.
If you are updating the application, the Readme.txt file on the Tektronix ftp site
supercedes the Readme.txt file on the floppy disk.
2. Power off the oscilloscope.
3. Insert the floppy disk in the floppy disk drive and power on the oscilloscope.
NOTE. To verify that the TDS Run-Time Environment V1.1 or above is installed,
watch for the name to appear at the top of the display when you power on the
oscilloscope. If it does not appear, contact your local Tektronix sales office.
After performing the power-up self-test, the oscilloscope automatically
begins the installation procedure.
As the application loads from the disk, the oscilloscope displays a clock icon
to indicate that it is busy. Also, the floppy disk drive LED is on, indicating
activity. If the clock icon continues to display after the floppy disk LED has
gone out, a problem has occurred with the installation. Repeat this proce-
dure. If the problem persists, contact your Tektronix representative.
TDSDDM1 Disk Drive Measurement Application User Manual
1–3
Installation
When the installation is complete, an Installation Complete message
displays.
4. Remove the floppy disk and cycle power to the oscilloscope.
Updates Through a Web Browser
If there is an update for this application, it will be available from the Tektronix
ftp site. To install an application update, you will need to download it from the
ftp site to a hard disk, copy it to a blank DOS-formatted floppy disk, and then
install it on your oscilloscope.
NOTE. More information about changes to the application or installation is in a
Readme.txt file on the ftp site. You should read it before you continue.
To copy the application from a web browser, follow these steps:
Disk Drive Connection
1. Access the ftp site at ftp://ftp.tek.com/mbd/support/00–index.html#1
2. Scroll through the files to the TDSJIT1 application, select the file, and
download it to your hard disk drive. If necessary, unzip the file.
3. Copy the application from the hard disk to a blank DOS-formatted floppy
disk.
4. Follow the Installing the Application procedure on page 1–3.
For best signal fidelity, we recommend you use a differential probe and two
standard probes. For connection to the Read channel signal, use a differential
probe, such as the Tektronix P6247 probe. For connection to the Index and
Sector signals, use standard oscilloscope probes, such as the Tektronix P6139A
passive probe or P6243 active probe.
There are two connection configurations, primary and secondary.
.
1–4
TDSDDM1 Disk Drive Measurement Application User Manual
Installation
Primary Setup
Use the primary setup if you want the oscilloscope to control the disk measurements. The primary setup is used for most configurations.
Connect the disk drive to the oscilloscope as shown in Figure 1–2.
Test oscilloscope
Disk drive
CH 1 CH 4
CH 3
Index signal (standard probe)
Sector signal (standard probe)
Read signal (differential probe)
Figure 1–2: Primary setup connections
Table 1–1 shows the default channel-to-signal assignments. You can change the
channel assignments to match your configuration. See Configuring the Input
Channels on page 1–11 for more information.
T able 1–1: Primary setup channel assignments
Channel Description
Ch 1 Read signal from the preamp channel
Ch 2 Read Gate signal (optional)
Ch 3 Sector pulse, marking the beginning of the sector on the track
Ch 4 Index pulse, marking the beginning of the track
NOTE. Some disk drives mark the beginning of a track by the absence of a sector
pulse. For this case, a timeout trigger setup is needed to identify the beginning
of the track. The Disk Drive Measurement Application does not support this
configuration.
TDSDDM1 Disk Drive Measurement Application User Manual
1–5
Installation
Secondary Setup
When using the secondary setup, you must specifically program the test
measurement control sequences.
Connect the disk drive to the oscilloscope as shown in Figure 1–3.
Test oscilloscope
Disk drive
CH 1 CH 2
Read Gate signal (standard probe)
Read signal (differential probe)
Figure 1–3: Secondary setup connections
1–6
TDSDDM1 Disk Drive Measurement Application User Manual
Configuration
This section describes configuration tasks that you should perform before you
start taking measurements. For the most part, these tasks configure the oscilloscope and Disk Drive Measurement Application to correctly acquire the signals
from the disk drive under test. Additional setup parameters, concerned more with
configuring specific measurements, are located in the Setup Parameters section
beginning on page 3–5.
Setting Up the Oscilloscope Trigger
Before starting measurements, you must manually set up the trigger, as described
in the following procedure:
1. Connect the Index, Sector, and Read signals to channels 4, 3, and 1
respectively.
2. Set the oscilloscope to the desired sample rate using the horizontal SCALE
knob. (The sample rate is usually 500 MS/s, or 1, 2, or 4 GS/s.)
3. Set the time interval:
a. Fit the waveform to the screen by pressing HORIZONTAL MENU ➞
Record Length (main) ➞ Fit to Screen (side). Select ON.
b. In the same menu, select a record length appropriate to the signal under
test.
4. Set up the trigger:
a. Set the trigger coupling to DC by pressing Coupling (main) ➞ DC
(side).
b. Set the slope by pressing Slope (main) and then selecting positive or
negative slope (side). (Select the slope appropriate to your disk drive
signal.)
c. Set the mode to Normal by pressing Mode & Holdoff (main) ➞ Normal
(side).
d. Set the level by pressing Level (main) and then selecting a level
appropriate to your signal.
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Configuration
Setting Up the Application Trigger
Before you begin taking measurements, you should specify the following trigger
parameters:
H Trigger Mode, which selects the input trigger signal
H Start/Stop Sector (used with the Sector Trigger Mode only), which specifies
the range of sectors to be measured
H Preamble Duration (used with the Sector Trigger Mode only), which the
application uses to automatically remove the preamble from the measurement calculations
Set up the trigger parameters as follows:
1. If you have not already done so, start the application as follows:
a. Press SETUP ➞ Select Application (main).
b. Using the general purpose knob, select hd0, and then press SELECT.
(Depending on previous actions, you might not need to do this step.)
c. Using the general purpose knob, select TDSDDM1.APP.
d. Press Activate Application (side).
2. Press Trigger (main) ➞ Mode (side). See Figure 1–4. Select one of the
following:
Sector Select Sector if you want to perform a measurement over a
range of sectors rather than over the entire track. The oscilloscope uses the main trigger to trigger on the Index pulse.
The delayed trigger is used to monitor sectors as follows:
Delayed trigger—triggerable after Events/Time
Delay Edge Source—Sector signal
Delay Count—sequences through sector numbers
Delay Time—preamble duration
Sector is the default Trigger Mode selection.
Read Gate Select Read Gate if you want to trigger on the Read Gate
signal. The delay trigger is not used with this selection.
User Select User if you want to use your own custom trigger set-
up. When you select User, the application does not alter the
trigger settings.
Index Select Index if you want to trigger on the Index signal. The
delay trigger is not used with this selection.
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3. If you selected the Sector mode, set the Start and Stop Sectors now using the
side menu selections.
TDSDDM1 Disk Drive Measurement Application User Manual
Configuration
4. Set the Preamble Duration. Using the general-purpose knob, select a value
that is greater than the actual signal preamble duration. This ensures that
none of the preamble is acquired and that the preamble is not included in the
measurement.
Figure 1–4: Selecting the sectors to measure
Hysteresis
Many of the measurements require a search for a local event called a peak and
trough pair. Set the hysteresis level so that noise will not cause false identification of peaks in the Read channel waveform. For a peak or trough to be found,
the signal must be greater than the hysteresis level.
Hysteresis is a global setting that is used by measurements such as TAA, PW50,
time asymmetry, and time between peaks.
TDSDDM1 Disk Drive Measurement Application User Manual
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Configuration
Peak
Signal
Hysteresis
setting
Noise
Trough
Figure 1–5: Using hysteresis to avoid false identification of peaks
Set the hysteresis levels as follows:
1. Press –menu– (main) to display the second page of menu selections.
2. Press Hysteresis (main) ➞ Hysteresis (side). See Figure 1–6.
3. Specify the hysteresis value.
The units for hysteresis are in divisions. The value you enter is used for the
positive hysteresis level and its negative is used for the negative level. For
example, if you enter a value of 2 divisions, the hysteresis levels are at +2
divisions and –2 divisions.
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TDSDDM1 Disk Drive Measurement Application User Manual
Configuration
Figure 1–6: Hysteresis menu
Configuring the Input Channels
If you are using the default channel configuration, this topic does not apply to
you.
In some cases, your configuration might not match the channel assignments used
by this Disk Drive Measurement Application. Table 1–2 lists the default input
channel assignments.
T able 1–2: Default input channel assignments
Channel Description
Ch 1 Read signal from the preamp channel
Ch 2 Read Gate signal (optional)
Ch 3 Sector pulse, marking the beginning of the sector on the track
Ch 4 Index pulse, marking the beginning of the track
1
This signal is used for triggering only when the Trigger/Mode/Read
Gate menu item has been selected.
2
This signal is used for triggering only when the Trigger/Mode/Sector
menu item has been selected.
1
2
2
TDSDDM1 Disk Drive Measurement Application User Manual
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Configuration
If necessary, you can reconfigure the input channels to match your configuration
using the Input Channels menu, as follows:
1. From the application display, go to the Input Channels menu by pressing
–menu– (main) ➞ Input Channels (side). See Figure 1–7.
2. Using the side menu buttons, assign the disk drive signals to the appropriate
channels.
1–12
Figure 1–7: The Input Channels menu
TDSDDM1 Disk Drive Measurement Application User Manual
Operating Basics
Functional Overview
This section describes how to use the basic functions of the Disk Drive
Measurement Application. Further details about the basic functions and
descriptions of more advanced features are included in the Reference section.
Starting the Application
After the Disk Drive Measurement Application has been installed in the
oscilloscope, start the application as follows:
1. Press SETUP ➞ Select Application (main). See Figure 2–1.
2. Using the general purpose knob, select hd0, and then press SELECT.
(Depending on previous actions, you might not need to do this step.)
3. Using the general purpose knob, select TDSDDM1.APP.
4. Press Activate Application (side).
The application starts up and displays as shown in Figure 2–2.
TDSDDM1 Disk Drive Measurement Application User Manual
2–1
Functional Overview
Figure 2–1: Starting the application
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TDSDDM1 Disk Drive Measurement Application User Manual
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