Unable to simulate GPIO DDR on modelsim 10.1d version.
It is showing that 'fiftyfivenm_ff' is missing. How to resolve this issue . Please help
C:/altera/13.1/modelsim_ase/altera/verilog/twentynm
# C:/altera/13.1/modelsim_ase/altera/vhdl/altera
# C:/altera/13.1/modelsim_ase/altera/verilog/220model
# C:/altera/13.1/modelsim_ase/altera/verilog/altera_lnsim
# C:/altera/13.1/modelsim_ase/altera/verilog/altera_mf
# C:/altera/13.1/modelsim_ase/altera/verilog/altera
# C:/altera/13.1/modelsim_ase/altera/verilog/max
# C:/altera/13.1/modelsim_ase/altera/verilog/220model
# C:/altera/13.1/modelsim_ase/altera/verilog/maxii
# F:/goldn_pen/Golden_Pen_Top_iputf_libs/DDR_Data
# F:/goldn_pen/rtl_work
# C:/altera/13.1/modelsim_ase/verilog
# C:/altera/13.1/modelsim_ase/modelsim_lib
# C:/altera/13.1/modelsim_ase/altera/verilog/twentynm
# C:/altera/13.1/modelsim_ase/altera/vhdl/altera
# F:/goldn_pen/Golden_Pen_Top_iputf_libs/DDR_Data
# ** Error: (vsim-3033) F:/goldn_pen/*/*/DDR_Data_sim/altera_gpio_lite/altera_gpio_lite.sv(743): Instantiation of 'fiftyfivenm_ff' failed. The design unit was not found.
Thanks