feat: add all testbench files

tb/apb4_uart_tb.sv

@@ -0,0 +1,48 @@
+// Copyright (c) 2023 Beijing Institute of Open Source Chip
+// uart is licensed under Mulan PSL v2.
+// You can use this software according to the terms and conditions of the Mulan PSL v2.
+// You may obtain a copy of Mulan PSL v2 at:
+//             http://license.coscl.org.cn/MulanPSL2
+// THIS SOFTWARE IS PROVIDED ON AN "AS IS" BASIS, WITHOUT WARRANTIES OF ANY KIND,
+// EITHER EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO NON-INFRINGEMENT,
+// MERCHANTABILITY OR FIT FOR A PARTICULAR PURPOSE.
+// See the Mulan PSL v2 for more details.
+
+`include "apb4_if.sv"
+`include "uart_define.sv"
+
+module apb4_uart_tb ();
+  localparam CLK_PEROID = 10;
+  logic rst_n_i, clk_i;
+
+  initial begin
+    clk_i = 1'b0;
+    forever begin
+      #(CLK_PEROID / 2) clk_i <= ~clk_i;
+    end
+  end
+
+  task sim_reset(int delay);
+    rst_n_i = 1'b0;
+    repeat (delay) @(posedge clk_i);
+    #1 rst_n_i = 1'b1;
+  endtask
+
+  initial begin
+    sim_reset(40);
+  end
+
+  apb4_if u_apb4_if (
+      clk_i,
+      rst_n_i
+  );
+
+  uart_if u_uart_if ();
+
+  test_top u_test_top (.apb4(u_apb4_if.master));
+  apb4_uart u_apb4_uart (
+      .apb4(u_apb4_if.slave),
+      .uart(u_uart_if.dut)
+  );
+
+endmodule