简单的cadence ic5141与ic610共存
测试平台fedora22，打开用户目录下的.bashrc, 加入下面的设置 如果用ic5141, 先输入ic51, 再输入icfb; ic61同理。
alias ic61='export cds_ver=ic610;
source .bashrc;
echo "virtuoso ver. ic610"'
alias ic51='export cds_ver=ic5141;
source .bashrc;echo "virtuoso ver. ic5141"'
export CDS_ROOT=/opt/cds/$cds_ver
export CDS_INST_DIR=/opt/cds/$cds_ver
export CDS_INSTALL_DIR=/opt/cds/$cds_ver
export OA_HOME=/opt/cds/ic615/OA
export CDS_LIC_FILE=$CDS_ROOT/share/license/license.dat
export CDS_Netlisting_Mode=Analog
export PATH=$CDS_ROOT/tools/bin:$CDS_ROOT/tools/dfII/bin:$PATH`