1 VCS的仿真过程主要包括两步：

1）编译

2）执行

VCS仿真学习（1）_VCS

2 addertb.v

module addertb;
reg [7:0] a_test, b_test;
wire [7:0] sum_test;
reg cin_test;
wire cout_test;
reg [17:0] test;

add8 u1(a_test, b_test, cin_test, sum_test, cout_test);

initial
begin
  for (test = 0; test <= 18'h1ffff; test = test +1) begin
    cin_test = test[16];
    a_test = test[15:8];
    b_test = test[7:0];
    #50;
    if ({cout_test, sum_test} !== (a_test + b_test + cin_test)) begin
      $display("***ERROR at time = %0d ***", $time);
      $display("a = %h, b = %h, sum = %h;  cin = %h, cout = %h",
               a_test, b_test, sum_test, cin_test, cout_test);
      $finish;
    end
    #50;
  end
  $display("*** Testbench Successfully completed! ***");
  $finish;
end
endmodule

3 makefile

```bash
#complie simulation coverage debug clean
.PHONY:com sim  cov debug clean

#output sim file 
OUTPUT =add

#code coverage command
CM = -cm line+cond+fsm+branch+tgl
CM_NAME = -cm_name ${OUTPUT}
CM_DIR = -cm_dir ./${OUTPUT}.vdb

VPD_NAME =+vdpfile+vcdplus.vpd
DUMP_VPD =+define+DUMP_VPD
VCS =vcs  -full64                                                      \
        -timescale=1ns/1ns                                             \
           -cpp g++-4.8 -cc gcc-4.8 -LDFLAGS -Wl,--no-as-needed         \
           +v2k                                                         \
          -debug_all                                                    \
          -o ${OUTPUT}                                                  \
          -l compile.log                                                \
        ${VPD_NAME}                                                     \
        ${DUMP_VPD}                                                     \
        ${CM}                                                           \
        ${CM_NAME}                                                      \
        ${CM_DIR}                                                       \
        -Mupdate                                                        \
        -cm_hier ./cov.cfg

SIM =./${OUTPUT} ${VPD_NAME} -l ${OUTPUT}.log                          \
        ${CM}                                                          \
        ${CM_NAME}                                                     \
        ${CM_DIR}

com:
        ${VCS} -f filelist.f
sim:
        ${SIM}

cov:
        dve -full64 -covdir *.vdb &
debug:
        dve -full64 -vpd  vcdplus.vpd &
clean:
        rm -rf ./csrc *.daidir *.log  simv* *.key *.vpd ./DVEfiles ${OUTPUT} *.vdb

4使用

make

VCS仿真学习（1）_VCS_02

make sim

VCS仿真学习（1）_bash_03