3
Measurement Clock Tests
48
DDR2(+LP) Compliance Testing Methods of Implementation
Absolute Low Pulse Width - tCL(abs) - Test Method of Implementation
The purpose of this test is to measure the absolute duty cycle of all the negative pulse widths within
a window of 202 consecutive cycles.
Signals of Interest
Mode Supported: LPDDR2 only
Signal cycle of interest: READ or WRITE
Signal(s) of Interest:
• Clock Signal
Signals required to perform the test on the oscilloscope:
• Pin Under Test, PUT - any signal of interest, as defined above
Test Definition Notes from the Specification
Test References
See Table 103 in the
JESD209-2B
.
Pass Condition
The absolute tCL measurement value should be within the conformance limits as specified in the
JEDEC specification.
Measurement Algorithm
Example input test signal: Frequency: 1 KHz, Number of cycles acquired: 202.
1 Find the average period, tCK(avg) for cycle 1-202.
2 Find the maximum low pulse width, PW
MAX
(s) for cycle 1-202.
3 Find the minimum low pulse width, PW
MIN
(s) for cycle 1-202.
4 Calculate PW
MAX
(tCK) = PW
MAX
(s)/tCK(avg).
5 Calculate PW
MIN
(tCK) = PW
MIN
(s)/tCK(avg).
6 Check PW
MAX
(tCK) and PW
MIN
(tCK) for the worst case values.
7 Compare the test result to the compliance test limit.
Table 19
LPDDR2 AC Timing Table
Parameter
Symbol
Min
Max
Min
t
CK
LPDDR2
Unit
1066
933
800
677
533
466*
5
400
333
266*
5
200*
5
Max.
Frequency
*4
533
466
400
333
266
233
200
166
133
100
MHz
Clock Timing
Absolute clock
LOW pulse
width (with
allowed jitter)
t
CL
(abs),
allowed
Min
0.43
t
CK
(avg)
Max
0.57
Содержание D9020DDRC
Страница 1: ...Keysight D9020DDRC DDR2 LP Compliance Test Application Methods of Implementation ...
Страница 10: ...10 DDR2 LP Compliance Testing Methods of Implementation ...
Страница 40: ...1 Installing the DDR2 Compliance Test Application 40 DDR2 LP Compliance Testing Methods of Implementation ...
Страница 46: ...2 Preparing to Take Measurements 30 DDR2 LP Compliance Testing Methods of Implementation ...
Страница 70: ...3 Measurement Clock Tests 54 DDR2 LP Compliance Testing Methods of Implementation ...
Страница 134: ...6 Single Ended Signals VIH VIL Data Mask Tests 118 DDR2 LP Compliance Testing Methods of Implementation ...
Страница 158: ...9 Single Ended Signals Overshoot Undershoot Tests 142 DDR2 LP Compliance Testing Methods of Implementation ...
Страница 186: ...10 Differential Signals AC Input Parameters Tests 170 DDR2 LP Compliance Testing Methods of Implementation ...
Страница 224: ...14 Clock Timing CT Tests 208 DDR2 LP Compliance Testing Methods of Implementation ...
Страница 270: ...15 Data Strobe Timing DST Tests 254 DDR2 LP Compliance Testing Methods of Implementation ...
Страница 342: ...17 Command and Address Timing CAT Tests 326 DDR2 LP Compliance Testing Methods of Implementation ...
Страница 366: ...19 Calibrating the Infiniium Oscilloscope and Probe 350 DDR2 LP Compliance Testing Methods of Implementation ...