Hi,
A design uses 2 re-drivers (DS80PCI402) between ~3 feet of cable that interconnects Host and End Point Device. I am having difficulty of getting Emphasis and Equalization tuned to achieve required Preshoots levels from P0 to P10 at 8Gb/s (Gen3 data rate). Using differential probe at the output of 1st re-driver (before cable) with Emphasis at L10 and Equalization of L1 it is observed that End Point device signaling is passed through with proper ratios for P0-P10 pre-shoots. The other differential probe is installed at the input of 2nd re-driver (after cable) it is observed that ratio of P0-P10 are preserved as well with amplitude dropped (expected). However probing PCIe signal at the output of 2nd re-driver it is observed that too much de-emphasis is present no matter what Emphasis Level and Equalization Levels are used. What am I doing wrong? All I am trying to do is boost somewhat disturbed signal through the High Speed Cable to make it PCIe Compliant from amplitude, jitter, and pre-shoot perspectives.
Thank you
