15
Data Strobe Timing (DST) Tests
248
DDR2(+LP) Compliance Testing Methods of Implementation
tQSH, DQS Output High Pulse Width - Test Method of Implementation
The purpose of this test is to verify that the width of the high level of the Data Strobe signal is within
the conformance limit as specified in the JEDEC specification.
Signals of Interest
Mode Supported: LPDDR2 only
Signal cycle of interest: READ
Signal(s) of Interest:
• Data Strobe Signal (supported by Data Signal)
Optional signal(s):
• Chip Select Signal (this signal is used to separate DQS signals from different rank of memory)
Signals required to perform the test on the oscilloscope:
• Data Signal, DQ
• Data Strobe Signal, DQS
• Chip Select Signal, CS (optional)
Test Definition Notes from the Specification
Test References
See Table 103 - LPDDR2 AC Timing Table in the
JESD209-2B
.
PASS Condition
The worst measured tQSH shall be within the specification limit.
Measurement Algorithm
1 Acquire and split read and write burst of the acquired signal.
2 Take the first valid READ burst found.
3 Find all valid rising and falling DQS crossing in this burst.
4 tQSH is the time interval starting from a rising edge of the DQS and ending at the following
falling edge.
5 Collect all tQSH.
6 Determine the worst result from the measured tQSH.
Table 168
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
Read Parameters*
14
DQS output high
pulse width
tQSH
Min
t
CH
(abs) - 0.05
t
CK
(avg)
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 ...