8051ipvhdl核编译不能通过,各位大侠看看是什么原因!帮忙啊!源代码为

我用的是xilinx foundation 3.1i编译里头的vhdl目录下的所有文件,但是结果总是有一个文件报错(mc8051_top_struc_cfg.vhd)编译出错,错误如下:
Error L72/C0 : #0 Error: D:/xilinx/active/projects/ip8051/mc8051_top_struc_cfg.vhd line 72 No selected element named MC8051_ROM_SIM_CFG is defined for this prefix. (VSS-573)
Error L75/C0 : #0 Error: D:/xilinx/active/projects/ip8051/mc8051_top_struc_cfg.vhd line 75 No selected element named MC8051_RAM_SIM_CFG is defined for this prefix. (VSS-573)
Error L78/C0 : #0 Error: D:/xilinx/active/projects/ip8051/mc8051_top_struc_cfg.vhd line 78 No selected element named MC8051_RAMX_SIM_CFG is defined for this prefix. (VSS-573)
3 error(s) 0 warning(s) found。
不知道是什么原因,希望帮忙分析一下,不胜感激!!!