Warning Messages Displayed for UniPHY External Memory Interfaces When Compiling for Stratix V Devices

Description

When compiling a design for Stratix V devices, the system may display numerous PLL-related warning messages similar to the following:

Warning: PLL(s) placed in location FRACTIONALPLL_X0_Y1_N0 do not have a PLL clock to compensate specified - the Fitter will attempt to compensate all PLL Warning: PLL(s) placed in location FRACTIONALPLL_X0_Y1_N0 use multiple different clock network types - the PLL will compensate for output clocks Warning: PLL cross checking found inconsistent PLL clock settings: Warning: Node: mem_if|controller_phy_inst|memphy_top_inst|pll1~FRACTIONAL_PLL|mcntout was found missing 1 generated clock that corresponds to a base clock with a period of: 8.000 Warning: Clock: mem_if|ddr3_pll_write_clk was found on node: mem_if|controller_phy_inst|memphy_top_inst|pll3|outclk with settings that do not match the following PLL specifications: Warning: -multiply_by (expected: 21, found: 4264000) Warning: -divide_by (expected: 5, found: 1000000) Warning: -phase (expected: 0.00, found: 90.00)

These warning messages are expected and can be ignored.

Resolution

There is no workaround for this issue. You can safely ignore the error messages.