axi: Add AXI register module and testbench

Signed-off-by: Alex Forencich <[email protected]>

rtl/axi/taxi_axi_register.f

@@ -0,0 +1,4 @@
+taxi_axi_register.sv
+taxi_axi_register_wr.sv
+taxi_axi_register_rd.sv
+taxi_axi_if.sv

rtl/axi/taxi_axi_register.sv

@@ -0,0 +1,94 @@
+// SPDX-License-Identifier: CERN-OHL-S-2.0
+/*
+
+Copyright (c) 2018-2025 FPGA Ninja, LLC
+
+Authors:
+- Alex Forencich
+
+*/
+
+`resetall
+`timescale 1ns / 1ps
+`default_nettype none
+
+/*
+ * AXI4 register
+ */
+module taxi_axi_register #
+(
+    // AW channel register type
+    // 0 to bypass, 1 for simple buffer, 2 for skid buffer
+    parameter AW_REG_TYPE = 1,
+    // W channel register type
+    // 0 to bypass, 1 for simple buffer, 2 for skid buffer
+    parameter W_REG_TYPE = 2,
+    // B channel register type
+    // 0 to bypass, 1 for simple buffer, 2 for skid buffer
+    parameter B_REG_TYPE = 1,
+    // AR channel register type
+    // 0 to bypass, 1 for simple buffer, 2 for skid buffer
+    parameter AR_REG_TYPE = 1,
+    // R channel register type
+    // 0 to bypass, 1 for simple buffer, 2 for skid buffer
+    parameter R_REG_TYPE = 2
+)
+(
+    input  wire logic   clk,
+    input  wire logic   rst,
+
+    /*
+     * AXI4 slave interface
+     */
+    taxi_axi_if.wr_slv  s_axi_wr,
+    taxi_axi_if.rd_slv  s_axi_rd,
+
+    /*
+     * AXI4 master interface
+     */
+    taxi_axi_if.wr_mst  m_axi_wr,
+    taxi_axi_if.rd_mst  m_axi_rd
+);
+
+taxi_axi_register_wr #(
+    .AW_REG_TYPE(AW_REG_TYPE),
+    .W_REG_TYPE(W_REG_TYPE),
+    .B_REG_TYPE(B_REG_TYPE)
+)
+axi_register_wr_inst (
+    .clk(clk),
+    .rst(rst),
+
+    /*
+     * AXI4 slave interface
+     */
+    .s_axi_wr(s_axi_wr),
+
+    /*
+     * AXI4 master interface
+     */
+    .m_axi_wr(m_axi_wr)
+);
+
+taxi_axi_register_rd #(
+    .AR_REG_TYPE(AR_REG_TYPE),
+    .R_REG_TYPE(R_REG_TYPE)
+)
+axi_register_rd_inst (
+    .clk(clk),
+    .rst(rst),
+
+    /*
+     * AXI4 slave interface
+     */
+    .s_axi_rd(s_axi_rd),
+
+    /*
+     * AXI4 master interface
+     */
+    .m_axi_rd(m_axi_rd)
+);
+
+endmodule
+
+`resetall