PCIE2-425/PCIE2-426 AND PCIE2-439/PCIE2-436
PCIe2-2712 PCI Express Gen2 Expansion System User’s Manual
5-7
Revision 1.0, February 2015
5.5.4
PCIe2-426/425 Output Swing, De-Emphasis and Receive Equalization
The transceiver silicon used on the PCIe2-426 and PCIe2-425 has eight steps of programmable de-
emphasis, four steps of output swing and eight steps of receive equalization. The PCIe2-426/425 has
three DIP switches to adjust these settings on the cable interface. The as-shipped-default DIP switch
configuration is what Cyclone Microsystems has determined is the best setting for Gen1 or Gen2
operation with both the 1m and 3m PCIe cables shipped with Cyclone PCIe Expansion systems. Users
should not change the DIP switch settings unless they have the proper test equipment to verify their
results. Users change de-emphasis, output swing and receive equalization at their own peril. The default
DIP switch configuration is shown below:
Table 5-2. PCIe2-426 Default DIP Switch Configuration
Table 5-3. PCIe2-425 Default DIP Switch Configuration
POSITION
SWITCH S1
SWITCH S2
SWITCH S3
1
OFF
OFF
ON
2
OFF
ON
ON
3
ON
ON
ON
4
ON
ON
OFF
POSITION
SWITCH S1
SWITCH S2
SWITCH S3
1
OFF
OFF
ON
2
OFF
ON
ON
3
ON
OFF
ON
4
ON
OFF
OFF
