【求助】：在ISE10.1功能仿真时正确，时序仿真结果出错 [ password, always, second, 程序, 记录

这是我的代码的一个模块，我拿来仿真了一下，在功能仿真时仿真结果正确，时序仿真的结果就不完全对，求达人帮忙看下有什么问题。
程序的主要功能就是把输入cmd的数据（cmd[4]=1时才会记录）记录在password里
module jlmm(password,cmd,clk,resetb
    );
input clk,resetb;
input[4:0]cmd;
reg[2:0]sub_state,next_sub_state;
output[15:0] password;
reg [15:0]password;
parameter      first=3'b000,
     second=3'b001,
     third=3'b010,
     fourth=3'b011,
     finish=3'b100;
[email=always@(posedge]always@(posedge[/email] clk or negedge resetb)
begin
if(!resetb)
  sub_state<=first;
else
  sub_state<=next_sub_state;
end
[email=always@(cmd]always@(cmd[/email] or sub_state)
begin
if(cmd[4]==1)
    case(sub_state)
    first:
     next_sub_state=second;
    second:
     next_sub_state=third;
    third:
     next_sub_state=fourth;
    fourth:
     next_sub_state=finish;
    finish:
     next_sub_state=finish;
    endcase
  else
   next_sub_state=sub_state;
end
[email=always@(posedge]always@(posedge[/email] clk or negedge resetb)
begin
if(!resetb)
  password<=0;
else if(cmd[4]==1)
  case(sub_state)
  first:
   password[15:12]<=cmd[3:0];
  second:
   password[11:8]<=cmd[3:0];
  third:
   password[7:4]<=cmd[3:0];
  fourth:
   password[3:0]<=cmd[3:0];
  default:
   password<=password;
  endcase
else
  password<=password;
end
endmodule