Sync Signal Error Test

CD PLAYER: Nakamichi
Model: CD Player 2
Serial Number: 12396
Test Point: J182 (GFS out)webassets/CD-Player2.JPG
UNIVERSAL
COUNTER: ELENCO F-1300
Input: A
LPF: ON
ATTN: x10
Probe: 1:1

CD1: Sony Test CD Type 3 (YEDS7)
CD2: Taichi Backup CD
CD Total Playtime: 45 min 54 sec
Total Synchronization Signals: 7350 * ( 45 * 60 + 54 ) = 20,241,900

 

  Order CD Errors Comment
First Iteration 1 CD2 292
2 CD2 292There was no reloading of disc into Transport since the previous test.
3 CD1 2964
4 CD1 3099There was no reloading of disc into Transport since the previous test.
Second Iteration 5 CD1 3147
6 CD2 335
7 CD1 2737
8 CD2 296
9 CD1 3160
10 CD2 305
11 CD1 2954
12 CD2 302
13 CD1 2663
14 CD2 306 

 

Mean Error

CD1 = 2960
CD2 = 304

Sync Signal Error Rate

CD1 = 2960/20,241,900 = 146 PPM
CD2 = 304/20,241,900 = 15 PPM

 

Corollary

If the synchronization signal error is caused by the jitter of the data stream, then: 1) Every time the synchronization signal has an error, the data adjacent to the synchronization signal will also have an error. 2) The greater the amount of jitter, the more data adjacent to the synchronization signal will have errors. From this we can infer that the number of erroneous data caused by data stream jitter is positively correlated with the degree of data stream jitter, and it grows exponentially.

Note: Only when the jitter of the data stream is greater than 7T, the servo system will make a judgment that the synchronization signal is wrong. Therefore, no synchronization signal error does not mean that there is no data error.

 Created by Chen

 Last revision date: Aug-2019