HP E1725C, Getting Started Manual

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Chapter 4 Demo Waveforms
Demo 2: Data-to-Clock
4-16 Getting Started Guide
4
Overview
The drive is formatted so a “start-of-sector” pulse is used to trigger the
TIA once for each sector. The start-of-sector pulse occurs 30
µ
s prior to the
beginning of the data portion of the sector. The data portion of the sector
is 200
µ
s in duration. There are 64 sectors around the track.
This is the TIA setup menu to make data-to-clock measurements on this
formatted drive. Notice that this screen is similar to the data-to-data
configuration used in demonstration 1. However, the time delay from the
trigger, and the acquisition time has been modified as this data was
captured from a different drive. Reading from left-to-right you can see
that the TIA will wait for a trigger, delay 27
µ
s and then measure for
200
µ
s. This sequence is repeated 64 times to build a histogram. The
acquisition contains 64 consecutive sectors of data-to-clock measurements.
Notice that the time delay from trigger was set too small (27
µ
s instead of
30
µ
s) and as a result, the TIA made a few measurements in the header
(non-data) region. These “errant” measurements will be used later to
further illustrate capabilities of the software.