$`$ttimescale $1$ns $/1$ps

module tb$()$;

reg clk $=0$;

wire $[2$:$0]$ floor;

reg rst $=0$;

reg $[2$:$0]$ button$\_$value $=0$;

reg button$\_$pressed $=0$;

reg error $=0$;

initial begin

rst;

@$($posedge clk$)$;

rst;

@$($posedge clk$)$;

if $($floor$!=0)$ begin error ; $display$("01$: Expected Floor $0!")$; end

button$\_$pressed ;

button$\_$value ;

@$($posedge clk$)$;

if $($floor$!=0)$ begin error ; $display$("02$: Expected Floor $0!")$; end

button$\_$pressed ;

@$($posedge clk$)$;

if $($floor$!=0)$ begin error ; $display$("03$: Expected Floor $0!")$; end

button$\_$pressed ;

@$($posedge clk$)$;

if $($floor$!=1)$ begin error ; $display$("04$: Expected Floor $1!")$; end

button$\_$pressed ;

@$($posedge clk$)$;

if $($floor$!=2)$ begin error ; $display$("05$: Expected Floor $2!")$; end

button$\_$pressed ;

button$\_$value ;

@$($posedge clk$)$;

if $($floor$!=3)$ begin error ; $display$("06$: Expected Floor $3!")$; end

button$\_$pressed ;

@$($posedge clk$)$;

if $($floor$!=4)$ begin error ; $display$("07$: Expected Floor $4!")$; end

button$\_$pressed ;

button$\_$value ;

@$($posedge clk$)$;

if $($floor$!=5)$ begin error ; $display$("08$: Expected Floor $5!")$; end

button$\_$pressed ;

@$($posedge clk$)$;

if $($floor$!=6)$ begin error ; $display$("09$: Expected Floor $6!")$; end

button$\_$pressed ;

@$($posedge clk$)$;

if $($floor$!=7)$ begin error ; $display$("10$: Expected Floor $7!")$; end

button$\_$pressed ;

@$($posedge clk$)$;

if $($floor$!=6)$ begin error ; $display$("11$: Expected Floor $6!")$; end

button$\_$pressed ;

@$($posedge clk$)$;

if $($floor$!=5)$ begin error ; $display$("12$: Expected Floor $5!")$; end

button$\_$pressed ;

button$\_$value ;

@$($posedge clk$)$;

if $($floor$!=4)$ begin error ; $display$("13$: Expected Floor $4!")$; end

button$\_$pressed ;

@$($posedge clk$)$;

if $($floor$!=3)$ begin error ; $display$("14$: Expected Floor $3!")$; end

button$\_$pressed ;

@$($posedge clk$)$;

if $($floor$!=2)$ begin error ; $display$("15$: Expected Floor $2!")$; end

button$\_$pressed ;

@$($posedge clk$)$;

if $($floor$!=3)$ begin error ; $display$("16$: Expected Floor $3!")$; end

button$\_$pressed ;

@$($posedge clk$)$;

if $($floor$!=4)$ begin error ; $display$("17$: Expected Floor $4!")$; end

button$\_$pressed ;

@$($posedge clk$)$;

if $($floor$!=5)$ begin error ; $display$("18$: Expected Floor $5!")$; end

@$($posedge clk$)$;

if $($floor$!=5)$ begin error ; $display$("19$: Expected Floor $5!")$; end

button$\_$pressed ;

button$\_$value ;

@$($posedge clk$)$;

if $($floor$!=5)$ begin error ; $display$("20$: Expected Floor $5!")$; end

button$\_$pressed ;

@$($posedge clk$)$;

if $($floor$!=5)$ begin error ; $display$("21$: Expected Floor $5!")$; end

button$\_$pressed ;

@$($posedge clk$)$;

if $($floor$!=4)$ begin error ; $display$("22$: Expected Floor $4!")$; end

button$\_$pressed ;

@$($posedge clk$)$;

if $($floor$!=3)$ begin error ; $display$("23$: Expected Floor $3!")$; end

button$\_$pressed ;

@$($posedge clk$)$;

if $($floor$!=2)$ begin error ; $display$("24$: Expected Floor $2!")$; end

button$\_$pressed ;

@$($posedge clk$)$;

if $($floor$!=1)$ begin error ; $display$("25$: Expected Floor $1!")$; end

button$\_$pressed ;

@$($posedge clk$)$;

if $($floor$!=0)$ begin error ; $display$("26$: Expected Floor $0!")$; end

button$\_$pressed ;

@$($posedge clk$)$;

if $($floor$!=0)$ begin error ; $display$("27$: Expected Floor $0!")$; end

button$\_$pressed ;

@$($posedge clk$)$;

if $($floor$!=0)$ begin error ; $display$("28$: Expected Floor $0!")$; end

button$\_$pressed ;

if $($error$==1)$ $display $("$Your elevator FAILED the test!"$)$;

else $display $("$Your elevator PASSED the test!"$)$;

$finish;

end

elevator dut $($

$.$i$\_$clk$($clk$),$

$.$i$\_$rst$($rst$),$

$.$i$\_$button$\_$pressed$($button$\_$pressed$),$

$.$i$\_$button$\_$value$($button$\_$value$),$

$.$o$\_$floor$($floor$)$

$)$;

always #$10$ clk $=$ ~clk;

endmodule

testbench code