add shift_register

shift_register/shift_register_tb.v

@@ -0,0 +1,48 @@
+`include "./shift_register/shift_register.v"
+
+module shift_register_tb;
+    reg clk, rst, load, shift_en, dir, serial_in;
+    reg [7:0] parallel_in;
+    wire [7:0] q;
+    wire serial_out;
+
+    shift_register register(
+        .clk(clk),
+        .rst(rst),
+        .load(load),
+        .shift_en(shift_en),
+        .dir(dir),
+        .serial_in(serial_in),
+        .parallel_in(parallel_in),
+        .q(q),
+        .serial_out(serial_out)
+    );
+
+    initial clk = 0;
+    always #5 clk = ~clk;
+
+    initial begin
+        $dumpfile("./shift_register/shift_register.vcd");
+        $dumpvars(0, shift_register_tb);
+
+        rst = 1; load = 0; shift_en = 1; dir = 0; serial_in = 0;
+        @(posedge clk);
+
+        $display("rst=%b, load=%b, shift_en=%b, dir=%b, serial_in=%b, q=%b", rst, load, shift_en, dir, serial_in, q);
+
+        rst = 0; load = 1; parallel_in = 64;
+        @(posedge clk);
+
+        $display("rst=%b, load=%b, shift_en=%b, dir=%b, serial_in=%b, q=%b", rst, load, shift_en, dir, serial_in, q);
+
+        load = 0; serial_in = 1;
+        @(posedge clk);
+        $display("rst=%b, load=%b, shift_en=%b, dir=%b, serial_in=%b, q=%b", rst, load, shift_en, dir, serial_in, q);
+
+        repeat(10) @(posedge clk);
+        $display("rst=%b, load=%b, shift_en=%b, dir=%b, serial_in=%b, q=%b", rst, load, shift_en, dir, serial_in, q);
+
+        $finish;
+    end
+
+endmodule