feat(L03): add blinker and synchronous logic card

tests/task03_pattern_rom_tb.sv

@@ -0,0 +1,32 @@
+module tb;
+    logic clk = 0;
+    logic rst = 1;
+    logic step = 0;
+    logic [2:0] phase;
+    logic [3:0] led;
+    logic [3:0] expected [0:9] = '{1, 2, 4, 8, 8, 4, 2, 1, 1, 2};
+    string trace_file;
+
+    pattern_rom dut (.*);
+    always #1 clk = ~clk;
+
+    initial begin
+        if ($value$plusargs("trace=%s", trace_file)) begin
+            $dumpfile(trace_file);
+            $dumpvars(0, tb);
+        end
+        repeat (2) @(posedge clk);
+        @(negedge clk);
+        rst = 0;
+        for (integer index = 0; index < 10; index += 1) begin
+            if (led != expected[index])
+                $fatal(1, "FAIL task03 index=%0d phase=%0d led=%0h expected=%0h", index, phase, led, expected[index]);
+            step = 1;
+            @(posedge clk); #1;
+            step = 0;
+            @(negedge clk);
+        end
+        $display("PASS task03 pattern=1,2,4,8,8,4,2,1 wrap=1,2");
+        $finish;
+    end
+endmodule