PCC D3400 - Data and Clock Pulsewidth

6.12.3 DATA AND CLOCK PULSEWIDTH
6.12.3.1 Test Configuration
(1) Remove the interface connector and terminator PCBA from connector J101 and
J1 02 on the Logic PCBA.
(2) Connect a disk exerciser having read/write capability to J101 or J102 on the Logic
PCBA.
(3) Apply power to the exerciser and the disk drive. Observe that the READY indicator
is illuminated;
allow a 5-minute warm up period.
(4) Write an all-ones pattern via the disk exerciser.
(5) Connect oscilloscope Channel 1 probe to TP25. Connect the test probe ground
clip to ground reference
TP17.
(6) Set oscilloscope Channel 1 sensitivity to 0.1 Ov per division.
(7) Set sync to internal, normal mode.
(8) Set oscilloscope to trigger on the positive slope of RPN.
(9) Connect oscilloscope Channel 2 probe to read data TP15 (or read clock TP16).
Connect the test probe ground clip
to ground reference TP17.
(10) Position sweep trace 1.3 cm below cener line of graticule.
(11) Set oscilloscope Channel 2 sensitivity to 0.10v per division.
6.12.3.2 Test Procedure
(1) Observe Read Data TP15 (or Read Clock TP16) on oscilloscope Channel 2 as
shown in Figure 6-20.
(2) Measure and note the pulsewidth.
(3) Acceptable Limits
• 100 nsec (minimum)
• 150 nsec (maximum)
6.12.3.3 Adjustment Procedure
If the acceptable limits detailed in Paragraph 6.12.3.2 Step (3) are exceeded perform the
following adjustment.
(1) Establish test configuration detailed in Paragraph 6.12.3.1.
(2) Adjust R153 (Read Data TP15) on R155 (Read Clock TP16) for 125 nsec at the 50
percent amplitude level.
READ DATA TP15 -----~ ~-----
50"10-1, It- 50%
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!-PUlSE WIDTH"'"
Figure 6-20. Read Clockl Read Data Pulsewidth