xfcp: Add XFCP switch module and testbench

Signed-off-by: Alex Forencich <alex@alexforencich.com>

tb/xfcp/taxi_xfcp_switch/test_taxi_xfcp_switch.sv

@@ -0,0 +1,54 @@
+// SPDX-License-Identifier: CERN-OHL-S-2.0
+/*
+
+Copyright (c) 2025 FPGA Ninja, LLC
+
+Authors:
+- Alex Forencich
+
+*/
+
+`resetall
+`timescale 1ns / 1ps
+`default_nettype none
+
+/*
+ * XFCP switch testbench
+ */
+module test_taxi_xfcp_switch #
+(
+    /* verilator lint_off WIDTHTRUNC */
+    parameter PORTS = 4
+    /* verilator lint_on WIDTHTRUNC */
+)
+();
+
+logic clk;
+logic rst;
+
+taxi_axis_if #(.DATA_W(8), .LAST_EN(1), .USER_EN(1), .USER_W(1)) up_xfcp_in(), up_xfcp_out();
+taxi_axis_if #(.DATA_W(8), .LAST_EN(1), .USER_EN(1), .USER_W(1)) dn_xfcp_in[PORTS](), dn_xfcp_out[PORTS]();
+
+taxi_xfcp_switch #(
+    .PORTS(PORTS)
+)
+uut (
+    .clk(clk),
+    .rst(rst),
+
+    /*
+     * XFCP upstream port
+     */
+    .up_xfcp_in(up_xfcp_in),
+    .up_xfcp_out(up_xfcp_out),
+
+    /*
+     * XFCP downstream ports
+     */
+    .dn_xfcp_in(dn_xfcp_in),
+    .dn_xfcp_out(dn_xfcp_out)
+);
+
+endmodule
+
+`resetall