3
Measurement Clock Tests
40
DDR2(+LP) Compliance Testing Methods of Implementation
Measurement Algorithm
Example input test signal: Frequency: 1 KHz, Number of cycles acquired: 202.
1 tERR(2per) is similar to tJIT(per), except it makes a small 2-cycle window inside the big 200 cycle
window and compares the average of the small window with the average of the big window.
2 Calculate the average for periods 1 to 200.
3 Calculate the average for periods 1 and 2.
4 Measure the difference of these two averages and save the answer as a measurement result.
5 Calculate the average of periods 2 and 3, and measure the difference between this average and
the big window average.
6 Continue with the same procedures until the average of periods 199 and 200 to the big window
average is compared. By now, 199 measurement results are generated.
7 Slide the big window by one and start comparing the average of periods 2 and 3 with the new big
window average until the comparison for periods 200 and 201 with the big window is completed.
By now, 199 more measurements are added, with the total of 398 measurement values.
8 Slide the big window by one again and repeat the same procedures. By now, 199 more
measurements are added, with the total of 597 measurement values.
9 Check the 597 results for the smallest and largest values (worst case values).
10 Compare the test results to the compliance test limits.
11 tERR(3per) is the same as tERR(2per) except the small window size is three periods wide.
tERR(4per) uses small window size of four periods, and tERR(5per) uses five periods.
12 tERR(6-10per) executes tERR(6per), tERR(7per), tERR(8per), tERR(9per) and tERR(10per),
combines all the measurement results together into one big pool, and checks for the smallest
and largest values.
13 tERR(11-50per) does the same for tERR(11per) through tERR(50per).
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 ...