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https://github.com/fpganinja/taxi.git
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xfcp: Add XFCP switch module and testbench
Signed-off-by: Alex Forencich <alex@alexforencich.com>
This commit is contained in:
4
rtl/xfcp/taxi_xfcp_switch.f
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4
rtl/xfcp/taxi_xfcp_switch.f
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@@ -0,0 +1,4 @@
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taxi_xfcp_switch.sv
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../prim/taxi_arbiter.sv
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../prim/taxi_penc.sv
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../axis/taxi_axis_if.sv
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677
rtl/xfcp/taxi_xfcp_switch.sv
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677
rtl/xfcp/taxi_xfcp_switch.sv
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@@ -0,0 +1,677 @@
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// SPDX-License-Identifier: CERN-OHL-S-2.0
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/*
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Copyright (c) 2017-2025 FPGA Ninja, LLC
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Authors:
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- Alex Forencich
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*/
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`timescale 1ns / 1ps
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/*
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* XFCP 1xN switch
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*/
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module taxi_xfcp_switch #
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(
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parameter PORTS = 4,
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parameter logic [15:0] XFCP_ID_TYPE = 16'h0100,
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parameter XFCP_ID_STR = "XFCP Switch",
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parameter logic [8*16-1:0] XFCP_EXT_ID = 0,
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parameter XFCP_EXT_ID_STR = ""
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)
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(
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input wire logic clk,
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input wire logic rst,
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/*
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* XFCP upstream port
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*/
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taxi_axis_if.snk up_xfcp_in,
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taxi_axis_if.src up_xfcp_out,
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/*
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* XFCP downstream ports
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*/
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taxi_axis_if.snk dn_xfcp_in[PORTS],
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taxi_axis_if.src dn_xfcp_out[PORTS]
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);
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parameter CL_PORTS = PORTS > 1 ? $clog2(PORTS) : 1;
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parameter CL_PORTS_P1 = $clog2(PORTS+1);
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// check configuration
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if (PORTS < 1 || PORTS > 256)
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$fatal(0, "Error: PORTS out of range; must be between 1 and 256");
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localparam START_TAG = 8'hFF;
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localparam RPATH_TAG = 8'hFE;
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localparam ID_REQ = 8'hFE;
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localparam ID_RESP = 8'hFF;
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// ID ROM
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localparam ID_PTR_W = (XFCP_EXT_ID != 0 || XFCP_EXT_ID_STR != 0) ? 6 : 5;
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localparam ID_ROM_SIZE = 2**ID_PTR_W;
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reg [7:0] id_rom[ID_ROM_SIZE];
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reg [ID_PTR_W-1:0] id_ptr_reg = '0, id_ptr_next;
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integer j;
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initial begin
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// init ID ROM
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for (integer i = 0; i < ID_ROM_SIZE; i = i + 1) begin
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id_rom[i] = 0;
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end
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// binary part
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{id_rom[1], id_rom[0]} = 16'h0100 | (XFCP_ID_TYPE & 16'h00FF); // module type (switch)
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id_rom[2] = 8'd1; // upstream port count
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id_rom[3] = 8'(PORTS); // downstream port count
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// string part
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// find string length
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j = 0;
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for (integer i = 1; i <= 16; i = i + 1) begin
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if (j == i-1 && (XFCP_ID_STR >> (i*8)) > 0) begin
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j = i;
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end
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end
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// pack string
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for (integer i = 0; i <= j; i = i + 1) begin
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id_rom[i+16] = XFCP_ID_STR[8*(j-i) +: 8];
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end
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if (XFCP_EXT_ID != 0 || XFCP_EXT_ID_STR != 0) begin
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// extended ID
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// binary part
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for (integer i = 0; i < 16; i = i + 1) begin
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id_rom[i+32] = XFCP_EXT_ID[8*i +: 8];
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end
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// string part
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// find string length
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j = 0;
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for (integer i = 1; i <= 16; i = i + 1) begin
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if (j == i-1 && (XFCP_EXT_ID_STR >> (i*8)) > 0) begin
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j = i;
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end
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end
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// pack string
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for (integer i = 0; i <= j; i = i + 1) begin
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id_rom[i+48] = XFCP_EXT_ID_STR[8*(j-i) +: 8];
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end
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end
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end
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localparam [2:0]
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DN_STATE_IDLE = 3'd0,
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DN_STATE_TRANSFER = 3'd1,
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DN_STATE_HEADER = 3'd2,
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DN_STATE_PKT = 3'd3,
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DN_STATE_ID = 3'd4;
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reg [2:0] dn_state_reg = DN_STATE_IDLE, dn_state_next;
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localparam [0:0]
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UP_STATE_IDLE = 1'd0,
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UP_STATE_TRANSFER = 1'd1;
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reg [0:0] up_state_reg = UP_STATE_IDLE, up_state_next;
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reg [CL_PORTS-1:0] dn_select_reg = '0, dn_select_next;
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reg dn_frame_reg = 1'b0, dn_frame_next;
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reg dn_enable_reg = 1'b0, dn_enable_next;
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reg [CL_PORTS_P1-1:0] up_select_reg = '0, up_select_next;
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reg up_frame_reg = 1'b0, up_frame_next;
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reg up_xfcp_in_tready_reg = 1'b0, up_xfcp_in_tready_next;
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reg [PORTS-1:0] dn_xfcp_in_tready_reg = '0, dn_xfcp_in_tready_next;
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wire [PORTS-1:0] dn_xfcp_out_tready;
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wire [PORTS-1:0] dn_xfcp_out_tvalid;
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// internal datapath
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reg [7:0] up_xfcp_out_tdata_int;
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reg up_xfcp_out_tvalid_int;
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reg up_xfcp_out_tready_int_reg = 1'b0;
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reg up_xfcp_out_tlast_int;
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reg up_xfcp_out_tuser_int;
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wire up_xfcp_out_tready_int_early;
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reg [7:0] dn_xfcp_out_tdata_int;
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reg [PORTS-1:0] dn_xfcp_out_tvalid_int;
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reg dn_xfcp_out_tready_int_reg = 1'b0;
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reg dn_xfcp_out_tlast_int;
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reg dn_xfcp_out_tuser_int;
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wire dn_xfcp_out_tready_int_early;
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reg [7:0] int_loop_tdata_reg = 8'd0, int_loop_tdata_next;
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reg int_loop_tvalid_reg = 1'b0, int_loop_tvalid_next;
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reg int_loop_tready;
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reg int_loop_tready_early;
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reg int_loop_tlast_reg = 1'b0, int_loop_tlast_next;
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reg int_loop_tuser_reg = 1'b0, int_loop_tuser_next;
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assign up_xfcp_in.tready = up_xfcp_in_tready_reg;
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// unpack interface array
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wire [PORTS+1-1:0] dn_xfcp_in_tready;
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wire [7:0] dn_xfcp_in_tdata[PORTS+1];
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wire [PORTS+1-1:0] dn_xfcp_in_tvalid;
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wire [PORTS+1-1:0] dn_xfcp_in_tlast;
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wire dn_xfcp_in_tuser[PORTS+1];
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for (genvar n = 0; n < PORTS; n = n + 1) begin
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assign dn_xfcp_in_tdata[n] = dn_xfcp_in[n].tdata;
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assign dn_xfcp_in_tvalid[n] = dn_xfcp_in[n].tvalid;
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assign dn_xfcp_in[n].tready = dn_xfcp_in_tready_reg[n];
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assign dn_xfcp_in_tlast[n] = dn_xfcp_in[n].tlast;
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assign dn_xfcp_in_tuser[n] = dn_xfcp_in[n].tuser;
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assign dn_xfcp_in_tready[n] = dn_xfcp_in[n].tready;
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end
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assign dn_xfcp_in_tdata[PORTS] = int_loop_tdata_reg;
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assign dn_xfcp_in_tvalid[PORTS] = int_loop_tvalid_reg;
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assign dn_xfcp_in_tlast[PORTS] = int_loop_tlast_reg;
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assign dn_xfcp_in_tuser[PORTS] = int_loop_tuser_reg;
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assign dn_xfcp_in_tready[PORTS] = int_loop_tready;
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// mux for downstream output control signals
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wire current_output_tvalid = dn_xfcp_out_tvalid[dn_select_reg];
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wire current_output_tready = dn_xfcp_out_tready[dn_select_reg];
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// mux for incoming downstream packet
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wire [7:0] current_input_tdata = dn_xfcp_in_tdata[up_select_reg];
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wire current_input_tvalid = dn_xfcp_in_tvalid[up_select_reg];
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wire current_input_tready = dn_xfcp_in_tready[up_select_reg];
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wire current_input_tlast = dn_xfcp_in_tlast[up_select_reg];
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wire current_input_tuser = dn_xfcp_in_tuser[up_select_reg];
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// downstream control logic
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always_comb begin
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dn_state_next = DN_STATE_IDLE;
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dn_select_next = dn_select_reg;
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dn_frame_next = dn_frame_reg;
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dn_enable_next = dn_enable_reg;
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id_ptr_next = id_ptr_reg;
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up_xfcp_in_tready_next = 1'b0;
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dn_xfcp_out_tdata_int = up_xfcp_in.tdata;
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dn_xfcp_out_tvalid_int = PORTS'(up_xfcp_in.tvalid && up_xfcp_in.tready && dn_enable_reg) << dn_select_reg;
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dn_xfcp_out_tlast_int = up_xfcp_in.tlast;
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dn_xfcp_out_tuser_int = up_xfcp_in.tuser;
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int_loop_tdata_next = int_loop_tdata_reg;
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int_loop_tvalid_next = int_loop_tvalid_reg && !int_loop_tready;
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int_loop_tlast_next = int_loop_tlast_reg;
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int_loop_tuser_next = int_loop_tuser_reg;
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if (up_xfcp_in.tready & up_xfcp_in.tvalid) begin
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// end of frame detection
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if (up_xfcp_in.tlast) begin
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dn_frame_next = 1'b0;
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dn_enable_next = 1'b0;
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end
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end
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case (dn_state_reg)
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DN_STATE_IDLE: begin
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// wait for incoming upstream packet
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up_xfcp_in_tready_next = 1'b1;
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id_ptr_next = '0;
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if (!dn_frame_reg && up_xfcp_in.tready && up_xfcp_in.tvalid) begin
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// start of frame
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dn_frame_next = 1'b1;
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if (up_xfcp_in.tdata == RPATH_TAG || up_xfcp_in.tdata == START_TAG) begin
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// packet for us
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int_loop_tdata_next = up_xfcp_in.tdata;
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int_loop_tvalid_next = up_xfcp_in.tvalid;
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int_loop_tlast_next = up_xfcp_in.tlast;
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int_loop_tuser_next = up_xfcp_in.tuser;
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up_xfcp_in_tready_next = int_loop_tready_early;
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if (up_xfcp_in.tdata == RPATH_TAG) begin
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// has rpath
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dn_state_next = DN_STATE_HEADER;
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end else begin
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// no rpath
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dn_state_next = DN_STATE_PKT;
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end
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end else begin
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// route packet
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dn_enable_next = 1'b1;
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dn_select_next = CL_PORTS'(up_xfcp_in.tdata);
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up_xfcp_in_tready_next = dn_xfcp_out_tready_int_early;
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dn_state_next = DN_STATE_TRANSFER;
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if (up_xfcp_in.tdata >= 8'(PORTS)) begin
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// out of range
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dn_enable_next = 1'b0;
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end
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end
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end else begin
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dn_state_next = DN_STATE_IDLE;
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end
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end
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DN_STATE_TRANSFER: begin
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// transfer upstream packet through proper downstream port
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if (up_xfcp_in.tready && up_xfcp_in.tvalid) begin
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// end of frame detection
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if (up_xfcp_in.tlast) begin
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dn_frame_next = 1'b0;
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dn_enable_next = 1'b0;
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dn_state_next = DN_STATE_IDLE;
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end else begin
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dn_state_next = DN_STATE_TRANSFER;
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end
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end else begin
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dn_state_next = DN_STATE_TRANSFER;
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end
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up_xfcp_in_tready_next = dn_xfcp_out_tready_int_early && dn_frame_next;
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end
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DN_STATE_HEADER: begin
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// loop back header
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up_xfcp_in_tready_next = int_loop_tready_early;
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if (up_xfcp_in.tready && up_xfcp_in.tvalid) begin
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int_loop_tdata_next = up_xfcp_in.tdata;
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int_loop_tvalid_next = 1'b1;
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int_loop_tlast_next = up_xfcp_in.tlast;
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int_loop_tuser_next = up_xfcp_in.tuser;
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// end of header detection
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if (up_xfcp_in.tdata == START_TAG) begin
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dn_state_next = DN_STATE_PKT;
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end else begin
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dn_state_next = DN_STATE_HEADER;
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end
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end else begin
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dn_state_next = DN_STATE_HEADER;
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end
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end
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DN_STATE_PKT: begin
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// packet type
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up_xfcp_in_tready_next = int_loop_tready_early;
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if (up_xfcp_in.tready && up_xfcp_in.tvalid) begin
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int_loop_tdata_next = up_xfcp_in.tdata;
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int_loop_tvalid_next = 1'b1;
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int_loop_tlast_next = up_xfcp_in.tlast;
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int_loop_tuser_next = up_xfcp_in.tuser;
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if (up_xfcp_in.tdata == ID_REQ) begin
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// ID packet
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int_loop_tdata_next = ID_RESP;
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int_loop_tlast_next = 1'b0;
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dn_state_next = DN_STATE_ID;
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end else begin
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// something else
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int_loop_tlast_next = 1'b1;
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int_loop_tuser_next = 1'b1;
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dn_state_next = DN_STATE_IDLE;
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end
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end else begin
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dn_state_next = DN_STATE_PKT;
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end
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end
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DN_STATE_ID: begin
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// send ID
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up_xfcp_in_tready_next = dn_frame_next;
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if (int_loop_tready) begin
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int_loop_tdata_next = id_rom[id_ptr_reg];
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int_loop_tvalid_next = 1'b1;
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int_loop_tlast_next = 1'b0;
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int_loop_tuser_next = 1'b0;
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id_ptr_next = id_ptr_reg + 1;
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if (id_ptr_reg == ID_ROM_SIZE-1) begin
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int_loop_tlast_next = 1'b1;
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dn_state_next = DN_STATE_IDLE;
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end else begin
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dn_state_next = DN_STATE_ID;
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end
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end else begin
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dn_state_next = DN_STATE_ID;
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end
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end
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default: begin
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dn_state_next = DN_STATE_IDLE;
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end
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endcase
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end
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// upstream control logic
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wire [PORTS+1-1:0] req;
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wire [PORTS+1-1:0] ack;
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wire [PORTS+1-1:0] grant;
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wire grant_valid;
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wire [CL_PORTS_P1-1:0] grant_index;
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// arbiter instance
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taxi_arbiter #(
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.PORTS(PORTS+1),
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.ARB_ROUND_ROBIN(1),
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.ARB_BLOCK(1),
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.ARB_BLOCK_ACK(1),
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.LSB_HIGH_PRIO(1)
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)
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arb_inst (
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.clk(clk),
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.rst(rst),
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.req(req),
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.ack(ack),
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.grant(grant),
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.grant_valid(grant_valid),
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.grant_index(grant_index)
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);
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assign req = dn_xfcp_in_tvalid & ~grant;
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assign ack = grant & dn_xfcp_in_tvalid & dn_xfcp_in_tready & dn_xfcp_in_tlast;
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always_comb begin
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up_state_next = UP_STATE_IDLE;
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up_select_next = up_select_reg;
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up_frame_next = up_frame_reg;
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up_xfcp_out_tdata_int = current_input_tdata;
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up_xfcp_out_tvalid_int = current_input_tvalid && current_input_tready && up_frame_reg;
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up_xfcp_out_tlast_int = current_input_tlast;
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up_xfcp_out_tuser_int = current_input_tuser;
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if (current_input_tready && current_input_tvalid) begin
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if (current_input_tlast) begin
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// end of frame detection
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up_frame_next = 1'b0;
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end
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end
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case (up_state_reg)
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UP_STATE_IDLE: begin
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// wait for incoming downstream packet
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if (grant_valid && up_xfcp_out_tready_int_reg) begin
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up_frame_next = 1'b1;
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up_select_next = grant_index;
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up_state_next = UP_STATE_TRANSFER;
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if (up_select_next == CL_PORTS_P1'(PORTS)) begin
|
||||
// internal loop; don't add port
|
||||
end else begin
|
||||
// prepend port to packet
|
||||
up_xfcp_out_tdata_int = 8'(grant_index);
|
||||
up_xfcp_out_tvalid_int = 1'b1;
|
||||
up_xfcp_out_tlast_int = 1'b0;
|
||||
up_xfcp_out_tuser_int = 1'b0;
|
||||
end
|
||||
end else begin
|
||||
up_state_next = UP_STATE_IDLE;
|
||||
end
|
||||
end
|
||||
UP_STATE_TRANSFER: begin
|
||||
// transfer downstream packet out through upstream port
|
||||
if (current_input_tvalid && current_input_tready) begin
|
||||
if (current_input_tlast) begin
|
||||
up_frame_next = 1'b0;
|
||||
up_state_next = UP_STATE_IDLE;
|
||||
end else begin
|
||||
up_state_next = UP_STATE_TRANSFER;
|
||||
end
|
||||
end else begin
|
||||
up_state_next = UP_STATE_TRANSFER;
|
||||
end
|
||||
end
|
||||
endcase
|
||||
end
|
||||
|
||||
always_comb begin
|
||||
dn_xfcp_in_tready_next = '0;
|
||||
|
||||
// int_loop_tready_early = 1'b0;
|
||||
|
||||
// generate ready signal on selected port
|
||||
if (up_select_next == CL_PORTS_P1'(PORTS)) begin
|
||||
// int_loop_tready_early = up_xfcp_out_tready_int_early && up_frame_next;
|
||||
end else begin
|
||||
dn_xfcp_in_tready_next = PORTS'(up_xfcp_out_tready_int_early && up_frame_next) << up_select_next;
|
||||
end
|
||||
end
|
||||
|
||||
always_comb begin
|
||||
int_loop_tready_early = up_xfcp_out_tready_int_early && up_frame_next;
|
||||
end
|
||||
|
||||
always_comb begin
|
||||
int_loop_tready = up_xfcp_out_tready_int_reg && up_frame_reg;
|
||||
end
|
||||
|
||||
always_ff @(posedge clk) begin
|
||||
dn_state_reg <= dn_state_next;
|
||||
up_state_reg <= up_state_next;
|
||||
|
||||
id_ptr_reg <= id_ptr_next;
|
||||
|
||||
dn_select_reg <= dn_select_next;
|
||||
dn_frame_reg <= dn_frame_next;
|
||||
dn_enable_reg <= dn_enable_next;
|
||||
|
||||
up_select_reg <= up_select_next;
|
||||
up_frame_reg <= up_frame_next;
|
||||
|
||||
up_xfcp_in_tready_reg <= up_xfcp_in_tready_next;
|
||||
dn_xfcp_in_tready_reg <= dn_xfcp_in_tready_next;
|
||||
|
||||
int_loop_tdata_reg <= int_loop_tdata_next;
|
||||
int_loop_tvalid_reg <= int_loop_tvalid_next;
|
||||
int_loop_tlast_reg <= int_loop_tlast_next;
|
||||
int_loop_tuser_reg <= int_loop_tuser_next;
|
||||
|
||||
if (rst) begin
|
||||
dn_state_reg <= DN_STATE_IDLE;
|
||||
up_state_reg <= UP_STATE_IDLE;
|
||||
dn_select_reg <= '0;
|
||||
dn_frame_reg <= 1'b0;
|
||||
dn_enable_reg <= 1'b0;
|
||||
up_select_reg <= '0;
|
||||
up_frame_reg <= 1'b0;
|
||||
up_xfcp_in_tready_reg <= 1'b0;
|
||||
dn_xfcp_in_tready_reg <= '0;
|
||||
int_loop_tvalid_reg <= 1'b0;
|
||||
end
|
||||
end
|
||||
|
||||
// upstream output datapath logic
|
||||
reg [7:0] up_xfcp_out_tdata_reg = 8'd0;
|
||||
reg up_xfcp_out_tvalid_reg = 1'b0, up_xfcp_out_tvalid_next;
|
||||
reg up_xfcp_out_tlast_reg = 1'b0;
|
||||
reg up_xfcp_out_tuser_reg = 1'b0;
|
||||
|
||||
reg [7:0] temp_up_xfcp_tdata_reg = 8'd0;
|
||||
reg temp_up_xfcp_tvalid_reg = 1'b0, temp_up_xfcp_tvalid_next;
|
||||
reg temp_up_xfcp_tlast_reg = 1'b0;
|
||||
reg temp_up_xfcp_tuser_reg = 1'b0;
|
||||
|
||||
// datapath control
|
||||
reg store_up_xfcp_int_to_output;
|
||||
reg store_up_xfcp_int_to_temp;
|
||||
reg store_up_xfcp_temp_to_output;
|
||||
|
||||
assign up_xfcp_out.tdata = up_xfcp_out_tdata_reg;
|
||||
assign up_xfcp_out.tkeep = '1;
|
||||
assign up_xfcp_out.tstrb = up_xfcp_out.tkeep;
|
||||
assign up_xfcp_out.tvalid = up_xfcp_out_tvalid_reg;
|
||||
assign up_xfcp_out.tlast = up_xfcp_out_tlast_reg;
|
||||
assign up_xfcp_out.tid = '0;
|
||||
assign up_xfcp_out.tdest = '0;
|
||||
assign up_xfcp_out.tuser = up_xfcp_out_tuser_reg;
|
||||
|
||||
// enable ready input next cycle if output is ready or the temp reg will not be filled on the next cycle (output reg empty or no input)
|
||||
assign up_xfcp_out_tready_int_early = up_xfcp_out.tready || (!temp_up_xfcp_tvalid_reg && (!up_xfcp_out_tvalid_reg || !up_xfcp_out_tvalid_int));
|
||||
|
||||
always_comb begin
|
||||
// transfer sink ready state to source
|
||||
up_xfcp_out_tvalid_next = up_xfcp_out_tvalid_reg;
|
||||
temp_up_xfcp_tvalid_next = temp_up_xfcp_tvalid_reg;
|
||||
|
||||
store_up_xfcp_int_to_output = 1'b0;
|
||||
store_up_xfcp_int_to_temp = 1'b0;
|
||||
store_up_xfcp_temp_to_output = 1'b0;
|
||||
|
||||
if (up_xfcp_out_tready_int_reg) begin
|
||||
// input is ready
|
||||
if (up_xfcp_out.tready || !up_xfcp_out_tvalid_reg) begin
|
||||
// output is ready or currently not valid, transfer data to output
|
||||
up_xfcp_out_tvalid_next = up_xfcp_out_tvalid_int;
|
||||
store_up_xfcp_int_to_output = 1'b1;
|
||||
end else begin
|
||||
// output is not ready, store input in temp
|
||||
temp_up_xfcp_tvalid_next = up_xfcp_out_tvalid_int;
|
||||
store_up_xfcp_int_to_temp = 1'b1;
|
||||
end
|
||||
end else if (up_xfcp_out.tready) begin
|
||||
// input is not ready, but output is ready
|
||||
up_xfcp_out_tvalid_next = temp_up_xfcp_tvalid_reg;
|
||||
temp_up_xfcp_tvalid_next = 1'b0;
|
||||
store_up_xfcp_temp_to_output = 1'b1;
|
||||
end
|
||||
end
|
||||
|
||||
always_ff @(posedge clk) begin
|
||||
if (rst) begin
|
||||
up_xfcp_out_tvalid_reg <= 1'b0;
|
||||
up_xfcp_out_tready_int_reg <= 1'b0;
|
||||
temp_up_xfcp_tvalid_reg <= 1'b0;
|
||||
end else begin
|
||||
up_xfcp_out_tvalid_reg <= up_xfcp_out_tvalid_next;
|
||||
up_xfcp_out_tready_int_reg <= up_xfcp_out_tready_int_early;
|
||||
temp_up_xfcp_tvalid_reg <= temp_up_xfcp_tvalid_next;
|
||||
end
|
||||
|
||||
// datapath
|
||||
if (store_up_xfcp_int_to_output) begin
|
||||
up_xfcp_out_tdata_reg <= up_xfcp_out_tdata_int;
|
||||
up_xfcp_out_tlast_reg <= up_xfcp_out_tlast_int;
|
||||
up_xfcp_out_tuser_reg <= up_xfcp_out_tuser_int;
|
||||
end else if (store_up_xfcp_temp_to_output) begin
|
||||
up_xfcp_out_tdata_reg <= temp_up_xfcp_tdata_reg;
|
||||
up_xfcp_out_tlast_reg <= temp_up_xfcp_tlast_reg;
|
||||
up_xfcp_out_tuser_reg <= temp_up_xfcp_tuser_reg;
|
||||
end
|
||||
|
||||
if (store_up_xfcp_int_to_temp) begin
|
||||
temp_up_xfcp_tdata_reg <= up_xfcp_out_tdata_int;
|
||||
temp_up_xfcp_tlast_reg <= up_xfcp_out_tlast_int;
|
||||
temp_up_xfcp_tuser_reg <= up_xfcp_out_tuser_int;
|
||||
end
|
||||
end
|
||||
|
||||
// downstream output datapath logic
|
||||
reg [7:0] dn_xfcp_out_tdata_reg = 8'd0;
|
||||
reg [PORTS-1:0] dn_xfcp_out_tvalid_reg = '0, dn_xfcp_out_tvalid_next;
|
||||
reg dn_xfcp_out_tlast_reg = 1'b0;
|
||||
reg dn_xfcp_out_tuser_reg = 1'b0;
|
||||
|
||||
reg [7:0] temp_dn_xfcp_out_tdata_reg = 8'd0;
|
||||
reg [PORTS-1:0] temp_dn_xfcp_out_tvalid_reg = '0, temp_dn_xfcp_out_tvalid_next;
|
||||
reg temp_dn_xfcp_out_tlast_reg = 1'b0;
|
||||
reg temp_dn_xfcp_out_tuser_reg = 1'b0;
|
||||
|
||||
// datapath control
|
||||
reg store_dn_xfcp_int_to_output;
|
||||
reg store_dn_xfcp_int_to_temp;
|
||||
reg store_dn_xfcp_temp_to_output;
|
||||
|
||||
assign dn_xfcp_out_tvalid = dn_xfcp_out_tvalid_reg;
|
||||
|
||||
for (genvar k = 0; k < PORTS; k = k + 1) begin
|
||||
assign dn_xfcp_out[k].tdata = dn_xfcp_out_tdata_reg;
|
||||
assign dn_xfcp_out[k].tkeep = '1;
|
||||
assign dn_xfcp_out[k].tstrb = dn_xfcp_out[k].tkeep;
|
||||
assign dn_xfcp_out[k].tvalid = dn_xfcp_out_tvalid_reg[k];
|
||||
assign dn_xfcp_out[k].tlast = dn_xfcp_out_tlast_reg;
|
||||
assign dn_xfcp_out[k].tid = '0;
|
||||
assign dn_xfcp_out[k].tdest = '0;
|
||||
assign dn_xfcp_out[k].tuser = dn_xfcp_out_tuser_reg;
|
||||
|
||||
assign dn_xfcp_out_tready[k] = dn_xfcp_out[k].tready;
|
||||
end
|
||||
|
||||
// enable ready input next cycle if output is ready or the temp reg will not be filled on the next cycle (output reg empty or no input)
|
||||
assign dn_xfcp_out_tready_int_early = ((dn_xfcp_out_tready & dn_xfcp_out_tvalid) != 0) || ((temp_dn_xfcp_out_tvalid_reg == 0) && ((dn_xfcp_out_tvalid == 0) || (dn_xfcp_out_tvalid_int == 0)));
|
||||
|
||||
always_comb begin
|
||||
// transfer sink ready state to source
|
||||
dn_xfcp_out_tvalid_next = dn_xfcp_out_tvalid_reg;
|
||||
temp_dn_xfcp_out_tvalid_next = temp_dn_xfcp_out_tvalid_reg;
|
||||
|
||||
store_dn_xfcp_int_to_output = 1'b0;
|
||||
store_dn_xfcp_int_to_temp = 1'b0;
|
||||
store_dn_xfcp_temp_to_output = 1'b0;
|
||||
|
||||
if (dn_xfcp_out_tready_int_reg) begin
|
||||
// input is ready
|
||||
if (((dn_xfcp_out_tready & dn_xfcp_out_tvalid) != 0) || (dn_xfcp_out_tvalid == 0)) begin
|
||||
// output is ready or currently not valid, transfer data to output
|
||||
dn_xfcp_out_tvalid_next = dn_xfcp_out_tvalid_int;
|
||||
store_dn_xfcp_int_to_output = 1'b1;
|
||||
end else begin
|
||||
// output is not ready, store input in temp
|
||||
temp_dn_xfcp_out_tvalid_next = dn_xfcp_out_tvalid_int;
|
||||
store_dn_xfcp_int_to_temp = 1'b1;
|
||||
end
|
||||
end else if ((dn_xfcp_out_tready & dn_xfcp_out_tvalid) != 0) begin
|
||||
// input is not ready, but output is ready
|
||||
dn_xfcp_out_tvalid_next = temp_dn_xfcp_out_tvalid_reg;
|
||||
temp_dn_xfcp_out_tvalid_next = '0;
|
||||
store_dn_xfcp_temp_to_output = 1'b1;
|
||||
end
|
||||
end
|
||||
|
||||
always_ff @(posedge clk) begin
|
||||
if (rst) begin
|
||||
dn_xfcp_out_tvalid_reg <= '0;
|
||||
dn_xfcp_out_tready_int_reg <= 1'b0;
|
||||
temp_dn_xfcp_out_tvalid_reg <= '0;
|
||||
end else begin
|
||||
dn_xfcp_out_tvalid_reg <= dn_xfcp_out_tvalid_next;
|
||||
dn_xfcp_out_tready_int_reg <= dn_xfcp_out_tready_int_early;
|
||||
temp_dn_xfcp_out_tvalid_reg <= temp_dn_xfcp_out_tvalid_next;
|
||||
end
|
||||
|
||||
// datapath
|
||||
if (store_dn_xfcp_int_to_output) begin
|
||||
dn_xfcp_out_tdata_reg <= dn_xfcp_out_tdata_int;
|
||||
dn_xfcp_out_tlast_reg <= dn_xfcp_out_tlast_int;
|
||||
dn_xfcp_out_tuser_reg <= dn_xfcp_out_tuser_int;
|
||||
end else if (store_dn_xfcp_temp_to_output) begin
|
||||
dn_xfcp_out_tdata_reg <= temp_dn_xfcp_out_tdata_reg;
|
||||
dn_xfcp_out_tlast_reg <= temp_dn_xfcp_out_tlast_reg;
|
||||
dn_xfcp_out_tuser_reg <= temp_dn_xfcp_out_tuser_reg;
|
||||
end
|
||||
|
||||
if (store_dn_xfcp_int_to_temp) begin
|
||||
temp_dn_xfcp_out_tdata_reg <= dn_xfcp_out_tdata_int;
|
||||
temp_dn_xfcp_out_tlast_reg <= dn_xfcp_out_tlast_int;
|
||||
temp_dn_xfcp_out_tuser_reg <= dn_xfcp_out_tuser_int;
|
||||
end
|
||||
end
|
||||
|
||||
endmodule
|
||||
Reference in New Issue
Block a user