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C link and D link timing Measurements
Measurements are done with a CSR read (LED read) using two tools. One is
1)
RockyLogic Ant16 logic analyzer
(2 ns resolution, USB interface to PC)
and the other one is 2) 400 MHz/2 Gs Tek scope. This measurement was done
with the ZPD firmware as of June-2004 (dd=0x14,finder=0x5,fitter=0x6,dm=0xa):
note for experts - the dd dcm phase with this one is -30.
1) RockyLogic Ant16 logic analyzer
Channel 0 (CLINK) and 1 (DLINK) shows the CSR read sequences and the
time difference is 326 ns, as it is indicated in the bottom horizontal bar.
2) Tek 400 MHz/2 Gs scope
Again the above has channel 1=CLINK and 2=DLINK, showing the CSR read sequences and the
time difference is 324 ns, as it is indicated in the top right corner.
Given the fact that the logic analyzer has 2 ns resolution, two measurements
seem consistent each other.
Eunil Won
Last
modified: Jun 29 2004 |
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