1 iff 如过满足条件则采样，iff可以理解为if

covergroup iff_cov;coverpoint tr.data iff(!vif.reset) ; //复位时不采样
endgroup

2 coverpoint和bin

covergroup name_bin ;coverpoint tr.kind {bins zero  = {0};            //1个bin 代表kind = 0bins low = {[1:3],7};        // 1个bin 代表1：3 或者7bins high[] = {[8:$]};       // (tr.kind最大值-8) 个binbins rem    = default;       // 剩余数值属于1个bin}                     
endgroup

忽略某些bin

bit[2:0] low_ports_0_5;	//只使用数值0-5
covergroup CoverPort;coverpoint low_ports_0_5 {ignore_bins hi = {[6,7]};		//忽略掉6,7两个仓}
endgroup

交叉覆盖率

covergroup Covport; port: coverpoint tr.port{bins port[] = {[0:$]};  //8
}kind: coverpoint tr.kind {bins zero = {0};  //1bins lo = {[1:3]};  //1bins hi [] = {[8:$]};   //8bins misc = default;  //1
}
cross kind, port {ignore bins hi = binsof(port) intersect {7}; ignore bins md = binsof(port) intersect {0} &&binsof (kind) intersect {[9:11]};  //排除port的0、7、[9:11]ignore bins lo = binsof (kind.lo); //排除kind的[1:3]
}
endgroup

如果只想关注交叉覆盖率，而不想关注单个coverpoint，可以通过设置权重option.weight = 0来将coverpoint的覆盖率忽略

covergroup cross_type_kind;type : coverpoint tr.type {option.weight = 0}kind : coverpoint tr.kind {option.weight = 0}cross type,kind{ignore_bins t1 =binsof(type)intersect{5};}
endgroup