vortex/hw/rtl/mem/VX_gbar_arb.sv

// Copyright © 2019-2023
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the 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.

`include "VX_define.vh"

module VX_gbar_arb #(
    parameter NUM_REQS = 1,
    parameter OUT_BUF  = 0,
    parameter `STRING ARBITER = "R"
) (
    input wire              clk,
    input wire              reset,

    VX_gbar_bus_if.slave    bus_in_if [NUM_REQS],
    VX_gbar_bus_if.master   bus_out_if
);

    localparam REQ_DATAW = `NB_WIDTH + `NC_WIDTH + `NC_WIDTH;

    // arbitrate request

    wire [NUM_REQS-1:0]                req_valid_in;
    wire [NUM_REQS-1:0][REQ_DATAW-1:0] req_data_in;
    wire [NUM_REQS-1:0]                req_ready_in;

    for (genvar i = 0; i < NUM_REQS; ++i) begin : g_req_data_in
        assign req_valid_in[i] = bus_in_if[i].req_valid;
        assign req_data_in[i] = {bus_in_if[i].req_id, bus_in_if[i].req_size_m1, bus_in_if[i].req_core_id};
        assign bus_in_if[i].req_ready = req_ready_in[i];
    end

    VX_stream_arb #(
        .NUM_INPUTS  (NUM_REQS),
        .NUM_OUTPUTS (1),
        .DATAW       (REQ_DATAW),
        .ARBITER     (ARBITER),
        .OUT_BUF     (OUT_BUF)
    ) req_arb (
        .clk        (clk),
        .reset      (reset),
        .valid_in   (req_valid_in),
        .ready_in   (req_ready_in),
        .data_in    (req_data_in),
        .data_out   ({bus_out_if.req_id, bus_out_if.req_size_m1, bus_out_if.req_core_id}),
        .valid_out  (bus_out_if.req_valid),
        .ready_out  (bus_out_if.req_ready),
        `UNUSED_PIN (sel_out)
    );

    // broadcast response

    reg rsp_valid;
    reg [`NB_WIDTH-1:0] rsp_id;

    always @(posedge clk) begin
        if (reset) begin
            rsp_valid <= 0;
        end else begin
            rsp_valid <= bus_out_if.rsp_valid;
        end
        rsp_id <= bus_out_if.rsp_id;
    end

    for (genvar i = 0; i < NUM_REQS; ++i) begin : g_bus_in_if
        assign bus_in_if[i].rsp_valid = rsp_valid;
        assign bus_in_if[i].rsp_id = rsp_id;
    end

endmodule