9
Single-Ended Signals Overshoot/Undershoot Tests
138
DDR2(+LP) Compliance Testing Methods of Implementation
Test References
See Table 24 - AC Overshoot/Undershoot Specification for Address and Control Pins and Table 25 -
AC Overshoot/Undershoot Specification for Clock, Data, Strobe and Mask Pins in the
JEDEC
Standard JESD79-2E
.
Also See Table 24 - AC Overshoot/Undershoot Specification for Address and Control Pins and Table
25 - AC Overshoot/Undershoot Specification for Clock, Data, Strobe and Mask Pins in the
JESD208
.
Also see Table 88 - LPDDR2 AC Overshoot/Undershoot Specification in the
JESD209-2B.
PASS Condition
The measured maximum voltage value of the test signal should be less than or equal to the
maximum overshoot value.
The calculated overshoot area value should be less than or equal to the maximum overshoot area
allowed.
Measurement Algorithm
1 Set the number of sampling points to 2M samples.
2 Sample/acquire signal data and perform signal conditioning to maximize the screen resolution
(vertical scale adjustment).
3 Use T
MAX
, V
MAX
to get a timestamp of the maximum voltage on all regions of acquired waveform.
4 Perform manual zoom on waveform to maximize peak area.
5 Find the edges before and after the Overshoot Point at the Supply Reference Level in order to
calculate the maximum overshoot length duration. The table below shows the supply reference
level for each pin group.
6 Calculate the overshoot amplitude.
Overshoot amplitude = V
MAX
- supply reference level. Refer to the table above.
7 Calculate the overshoot area (V-ns)
a
Area of calculation is based on the area of calculation of a triangle where the overshoot width
is used as the triangle base and the overshoot amplitude is used as the triangle height.
b
Area = 0.5 * base * height.
8 Compare the test results with the compliance test limits.
Pin
Supply Reference Level
DDR2 Address and Control Pin
V
DD
DDR2 Clock, Data, Strobe, and Mask Pin
V
DDQ
LPDDR2 Address, Control, Clock, Chip Select and Clock Enable
V
DDCA
LPDDR2 Data, Strobe, Mask
V
DDQ
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 ...