如题,编译的工程是用MIG生成的DDR2控制器,自己为了测试添加了几个模块,写了一个顶层文件,并且根据自己的板子调整了UCF文件,在综合的时候出现了下面的问题,百思不得其解。求哪位能知道这是为什么嘛?要怎么改正呢?
ERROR:LIT:600 - IOBUFDS symbol
"XLXI_1/u_ddr2_top_0/u_mem_if_top/u_phy_top/u_phy_io/gen_dqs[0].u_iob_dqs/gen_dqs_iob_ddr2.u_iobuf_dqs" (output
signal=XLXI_1/u_ddr2_top_0/u_mem_if_top/u_phy_top/u_phy_io/gen_dqs[0].u_iob_d
qs/dqs_ibuf) does not have IOSTANDARD specified. Map is unable to generate a
default IOSTANDARD for IOBUFDS, one has to be explicitly provided.
Errors found during logical drc.
Design Summary
--------------
Number of errors : 1
Number of warnings : 0
Process "Map" failed
Preparing to edit top.ucf...