refclk_125_p I/O Standard
The Cyclone® IV GX Transceiver Starter Kit example designs for Quartus® II software version 9.1 have an issue with a missing voltage standard for refclk_125_p which defaults to 2.5V. To correct this problem, use the Assignment Editor to add and enable an I/O Standard of LVDS to the refclk_125_p pin or add the following assignment to the .qsf file:
set_instance_assignment -name IO_STANDARD LVDS -to refclk_125_p
pcie_refclk_p I/O Standard
The Cyclone IV GX Transceiver Starter Kit for Quartus II software version 9.1 includes an example design called golden_top. This design is missing an I/O Standard for the pcie_refclk_p pin, which is required for PCI Express operation. To use PCIe on this development kit, use the Assignment Editor to add and enable an I/O Standard of HCSL to the pcie_refclk_p pin or add the following assignment to the golden_top.qsf file:
set_instance_assignment -name IO_STANDARD HCSL -to pcie_refclk_p
Eye Diagram
The Cyclone IV GX Transceiver Starter Kit for Quartus II software version 9.1 includes an example design called bts_xcvr in the board_test_system folder. This design requires an update in the transmitter PMA settings to improve the eye diagram. This update is available in the September 2010 release.
PCIE_TX and PCIE_RX off page symbols
The Cyclone IV GX Transceiver Starter Kit schematic Rev B shows four of the off page symbols going the wrong direction on sheet 8. The affected signals are PCIE_RX_P, PCIE_RX_N, PCIE_TX_P, and PCIE_TX_N. There is no problem with the board connections, this is a labeling issue which affects the readability of the schematic.
Sheet 8 has the PCIe edge connector. The PCIE_RX_P/N pins drive off of this sheet to sheet 6, the off page arrows should point to the right in the same way the PCIE_REFCLK_P/N pins point to the right. The PCIE_TX_P/N pins are driven off of sheet 6 and received on Sheet 8 to drive out of the PCIe connector, the off page arrows should point to the left.
Termination value of Transceiver (Receiver)
Compiling the bts_xcvr reference design in Quartus II 10.0 and Quartus II 10.0 SP1 you will get the following error @“Error: Parameter "termination" of instance "receive_pma0" has illegal value "OCT 100 Ohms".
Please refer to the "Related Solutions" below to fix the error shown above.