3
Measurement Clock Tests
50
DDR2(+LP) Compliance Testing Methods of Implementation
Pass Condition
The tJIT(duty) 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.
tJIT(CH)
1 This measurement measures the difference between every high pulse width inside a 200 cycle
window with the average of the whole window.
2 Calculate the average for high pulse widths 1 to 200.
3 Measure the difference between high pulse width #1 with the average and save the answer as a
measurement result.
4 Measure the difference between high pulse width #2 with the average and save the answer as a
measurement result.
5 Continue the same procedures until the comparison for high pulse width #200 with the average is
completed. By now, 200 measurement results are generated.
6 Slide the window by one and measure the average of 2-201.
7 Compare high pulse width #2 with the new average. Continue the comparison for high pulse
width #3, #4, … #200, #201. By now, 200 more measurement results are added, with the total of
400 values.
8 Slide the window by one and measure the average of 3-202.
9 Compare high pulse width #3 with the new average. Continue the comparison for high pulse
width #4, #5, … #201, #202. By now, 200 more measurement results are added, with the total of
600 values.
10 Check these 600 results for the smallest and largest values (worst cases values).
11 Compare the test results against the compliance test limits.
tJIT(LH)
1 This measurement is similar to tJIT(CH) above except, instead of using high pulse widths, it uses
LOW pulse widths for testing comparison.
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 ...