请教FPGA error

atlandis

我在FPGA设计里面例化个sram，然后综合有下面的报错，请教是什么原因呢？


ERROR:MapLib:978 - LUT5 symbol "u2_scaler/dut/u_shf_datwin/Mmux_n018381" (output
   signal=u2_scaler/sram5_ada<7>) has an equation that uses input pin I4, which
   no longer has a connected signal. Please ensure that all the pins used in the
   equation for this LUT have signals that are not trimmed (see Section 5 of the
   Map Report File for details on which signals were trimmed).

alhoceima111

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