Introduction

The 2.45 release incorporates new features introduced after the WITE32 2.44 release. (This document uses the WITE32 2.44 release notes as a base line for comparison.)

1. Improved repeatability of overwrite measurements for both standalone Overwrite test and integrated Parametric test. The higher overwrite repeatability is achieved due to a mandatory band erase preconditioning and modified sequ ence of read/write operations. An attached addendum illustrates achieved repeatability of overwrite and other parametric measurements.
2. Improved repeatability of most parametric and WROffset measurements in the multi zone production sequence mode for S-1701A and S-1701CF spinstands. Please note that higher repeatability is achieved by making spinstand movements between zones smoother . The WITE32 ver.2.45 software adds about 1 second per zone to test time.
3. The name of overwrite result reported by the standalone Overwrite test is changed to ‘OvwrSA’ to avoid collision with the overwrite result name ‘Overwrite’ reported by integrated Parametric test.
4. The Preconditioning frame removed from the Overwrite test configuration dialogue box. The Overwrite test now involves mandatory band erase preconditioning. The band erase operation includes three tracks with offsets: T₁=–min (20µInch, TrackSize/2); T₂=0 µInch; T₃=min(20 µInch, TrackSize/2), where TrackSize is a size of the track specified in the Driver Parameters dialogue box. The Driver Parameters dialogue box is opened by clicking the Edit Driver Parameters button from the Product Selection dialogue box on WITE32 startup.

New layout of the Overwrite test configuration dialogue box in WITE32 ver. 2.45 is shown below:



5. Initialization procedure for TDA 5366 head amplifier was modified. During initialization head amplifier goes to the Standby mode first, then to the Active mode.
6. Support for GUZIK4UM head amplifier board P/N 313230, 311940.
7. Initialization procedure for 1611A head stack was modified. Switching of ENB_BIAS bit is removed.

Fixed Bugs

1. Noise spikes at the output of an analog box ANA971++A and/or ANA985 in servo mode.
2. Crash protection for headstacks does not work with spinstands that have Piezo DSP controller board P/N 313130.
3. "PLO fails, 2F period – XXXXX" error message on device start when system clock is set to frequency over 830 Mbit/s.
4. Four servo parameters are not updated after changing zone/setup: Track Width, Burst Frequency, Coarse Attenuator, and Fine Amplifier.

Addendum 1. Parametric results repeatability.

To evaluate a parametric results repeatability, we run a production sequence that includes three zones ID, MD and OD; in each zone we performed the following tests/operations:

• Band Erase operation
• WRoffset test (1 iteration, no averaging)
• Parametric test (1 iteration, no averaging)

We run this production sequence 300 times to get a representative statistics, so the head moved from zone to zone before each run of the Band Erase, WROffset, and Parametric test. No head load/unload was done during this evaluation. Our conditions of measurements were:

• Spinstand type: S-1701A
• RWA type: RWA-2550++A
• Servo mode: OFF
• RPM: 7200
• Head Write Width: 21 µinch
• Head Read Width: 13 µinch
• Disk thickness: 0.0315"

Below please find:

• Bar plot that shows peak-to-peak deviation of the
• Overwrite test result in three zones ID, MD, OD. Overwrite, PW50 and TAA results over 300 production runs.
• Two-dimensional scatter plots of the Overwrite, PW50 and TAA results versus WROffset measurement results.

Figure 1. Peak-to-Peak Deviation of the Overwrite test results

Figure 2. Overwrite results repeatability

Figure 3. PW50 results repeatability

Figure 4. TAA results repeatability

Figure 5. WROffset results repeatability