Due to a problem in the Quartus® II software version 11.1, the derive_pll_clocks
command may fail to generate all the necessary clocks for Cyclone® IV GX PCI Express designs. You may see warnings similar to the following in the TimeQuest timing analyzer:
Warning (332087): The master clock for this clock assignment could not be derived.
Clock: <user hierarchy>|hiptxclkout was not created.
Warning (332086): Ignoring clock spec: <user hierarchy>|cyclone_iii.cycloneiv_hssi_pcie_hip|pclkch0 Reason:
Clock derived from ignored clock: <user hierarchy>|transmit_pcs0|hiptxclkout. Clock assignment is being ignored.
Warning (332086): Ignoring clock spec: <user hierarchy>|cyclone_iii.cycloneiv_hssi_pcie_hip|coreclkout Reason:
Clock derived from ignored clock: <user hierarchy>|cyclone_iii.cycloneiv_hssi_pcie_hip|pclkch0. Clock assignment is being ignored.
Due to this problem, certain transceiver clocks may not be correctly constrained in your design and the IP may not function correctly in hardware.
A patch is available to fix this problem for the Quartus II software version 11.1. Download and install Patch 0.09 from the appropriate link below.
- Download the Quartus II software version 11.1 patch 0.09 for Windows (.exe)
- Download the Quartus II software version 11.1 patch 0.09 for Linux (.tar)
- Download the Readme for the Quartus II software version 11.1 patch 0.09 (.txt)
This problem is fixed beginning with the Quartus II software version 11.1 SP1.