DDR2(+LP) Compliance Testing Methods of Implementation
139
Single-Ended Signals Overshoot/Undershoot Tests
9
AC Undershoot Test Method of Implementation
The Undershoot Test can be divided into two sub-tests: Undershoot amplitude and Undershoot area.
The purpose of this test is to verify that the undershoot value of the test signal within a user-specific
region is lower than or equal to the conformance limit of the maximum peak amplitude allowed for
undershoot test as specified in the JEDEC specification.
When there is an undershoot, the undershoot area is calculated based on the undershoot width. The
undershoot area should be lower than or equal to the conformance limit of the maximum undershoot
area allowed as specified in the JEDEC specification.
Signals of Interest
Mode Supported: DDR2, LPDDR2
Signal cycle of interest: READ or WRITE
Signal(s) of Interest:
• Data Signal OR
• Data Strobe Signal OR
• Address Signal OR
• Control Signal OR
• Data Mask Control Signal OR
• 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
Table 86
AC Undershoot Specification for Address and Control Pins
A0-A15, BA0-BA2, CS, RAS, CAS, WE, CKE, ODT
Parameter
Specification
DDR2-400
DDR2-533
DDR2-667
DDR2-800
Maximum peak amplitude allowed for undershoot area
0.5(0.9)
1
V
0.5(0.9)
1
V
0.5(0.9)
1
V
0.5(0.9)
1
V
Maximum undershoot area below V
SS
1.33 V-ns
1.0 V-ns
0.8 V-ns
0.66 V-ns
Table 87
AC Undershoot Specification for Clock, Data, Strobe and Mask Pins
DQ, (U/L/R)DQS, (U/L/R)DQS, DM, CK, CK
Parameter
Specification
DDR2-400
DDR2-533
DDR2-667
DDR2-800
Maximum peak amplitude allowed for undershoot area
0.5 V
0.5 V
0.5 V
0.5 V
Maximum undershoot area below V
SSQ
0.38 V-ns
0.28 V-ns
0.23 V-ns
0.23 V-ns
Summary of Contents for D9020DDRC
Page 1: ...Keysight D9020DDRC DDR2 LP Compliance Test Application Methods of Implementation ...
Page 10: ...10 DDR2 LP Compliance Testing Methods of Implementation ...
Page 46: ...2 Preparing to Take Measurements 30 DDR2 LP Compliance Testing Methods of Implementation ...
Page 70: ...3 Measurement Clock Tests 54 DDR2 LP Compliance Testing Methods of Implementation ...
Page 224: ...14 Clock Timing CT Tests 208 DDR2 LP Compliance Testing Methods of Implementation ...
Page 270: ...15 Data Strobe Timing DST Tests 254 DDR2 LP Compliance Testing Methods of Implementation ...