用DC逻辑综合的时候输入check_timing之后报错

thrallzy

报错如下信息
Error: Can't find the specified library 'NangateOpenCellLibrary_slow_ecsm.db:NangateOpenCellLibrary' in memory. (UID-131)
Error: Can't find the specified library 'NangateOpenCellLibrary_slow_ecsm.db:NangateOpenCellLibrary' in memory. (UID-131)

然后我将.synopsys_dc.setup中的target library 和 link library从ccs改成ecsm之后就变成如下报错

Error: Can't find the specified library 'NangateOpenCellLibrary_slow_ccs.db:NangateOpenCellLibrary' in memory. (UID-131)
Error: Can't find the specified library 'NangateOpenCellLibrary_slow_ccs.db:NangateOpenCellLibrary' in memory. (UID-131)

当且仅当我将target library 和 link library同时用ccs和ecsm才不会报错
这是什么原因呢？