dmi_cdc.sv

/* Copyright 2018 ETH Zurich and University of Bologna.
 * Copyright and related rights are licensed under the Solderpad Hardware
 * License, Version 0.51 (the “License”); you may not use this file except in
 * compliance with the License.  You may obtain a copy of the License at
 * http://solderpad.org/licenses/SHL-0.51. Unless required by applicable law
 * or agreed to in writing, software, hardware and materials distributed under
 * this License is distributed on an “AS IS” BASIS, WITHOUT WARRANTIES OR
 * CONDITIONS OF ANY KIND, either express or implied. See the License for the
 * specific language governing permissions and limitations under the License.
 *
 * File:   axi_riscv_debug_module.sv
 * Author: Andreas Traber <atraber@iis.ee.ethz.ch>
 * Author: Florian Zaruba <zarubaf@iis.ee.ethz.ch>
 *
 * Description: Clock domain crossings for JTAG to DMI very heavily based
 *              on previous work by Andreas Traber for the PULP project.
 *              This is mainly a wrapper around the existing CDCs.
 */
module dmi_cdc (
    // JTAG side (master side)
    input  logic             tck_i,
    input  logic             trst_ni,

    input  dm::dmi_req_t     jtag_dmi_req_i,
    output logic             jtag_dmi_ready_o,
    input  logic             jtag_dmi_valid_i,

    output dm::dmi_resp_t    jtag_dmi_resp_o,
    output logic             jtag_dmi_valid_o,
    input  logic             jtag_dmi_ready_i,

    // core side (slave side)
    input  logic             clk_i,
    input  logic             rst_ni,

    output dm::dmi_req_t     core_dmi_req_o,
    output logic             core_dmi_valid_o,
    input  logic             core_dmi_ready_i,

    input dm::dmi_resp_t     core_dmi_resp_i,
    output logic             core_dmi_ready_o,
    input  logic             core_dmi_valid_i
  );

  cdc_2phase #(.T(dm::dmi_req_t)) i_cdc_req (
    .src_rst_ni  ( trst_ni          ),
    .src_clk_i   ( tck_i            ),
    .src_data_i  ( jtag_dmi_req_i   ),
    .src_valid_i ( jtag_dmi_valid_i ),
    .src_ready_o ( jtag_dmi_ready_o ),

    .dst_rst_ni  ( rst_ni           ),
    .dst_clk_i   ( clk_i            ),
    .dst_data_o  ( core_dmi_req_o   ),
    .dst_valid_o ( core_dmi_valid_o ),
    .dst_ready_i ( core_dmi_ready_i )
  );

  cdc_2phase #(.T(dm::dmi_resp_t)) i_cdc_resp (
    .src_rst_ni  ( rst_ni           ),
    .src_clk_i   ( clk_i            ),
    .src_data_i  ( core_dmi_resp_i  ),
    .src_valid_i ( core_dmi_valid_i ),
    .src_ready_o ( core_dmi_ready_o ),

    .dst_rst_ni  ( trst_ni          ),
    .dst_clk_i   ( tck_i            ),
    .dst_data_o  ( jtag_dmi_resp_o  ),
    .dst_valid_o ( jtag_dmi_valid_o ),
    .dst_ready_i ( jtag_dmi_ready_i )
  );
endmodule