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//
// Copyright 2016 Ettus Research
// Copyright 2018 Ettus Research, a National Instruments Company
//
// SPDX-License-Identifier: LGPL-3.0-or-later
//
// AXI-Stream multipler with select line
//
module axi_mux_select #(
parameter WIDTH = 32,
parameter PRE_FIFO_SIZE = 0,
parameter POST_FIFO_SIZE = 0,
parameter SWITCH_ON_LAST = 0, // Wait until tlast is asserted before updating
parameter SIZE = 4)
(
input clk, input reset, input clear,
input [$clog2(SIZE)-1:0] select,
input [SIZE*WIDTH-1:0] i_tdata, input [SIZE-1:0] i_tlast, input [SIZE-1:0] i_tvalid, output [SIZE-1:0] i_tready,
output [WIDTH-1:0] o_tdata, output o_tlast, output o_tvalid, input o_tready
);
wire [WIDTH*SIZE-1:0] i_tdata_int;
wire [WIDTH-1:0] i_tdata_arr[0:SIZE-1];
wire [SIZE-1:0] i_tlast_int, i_tvalid_int, i_tready_int;
wire [WIDTH-1:0] o_tdata_int;
wire o_tlast_int, o_tvalid_int, o_tready_int;
genvar n;
generate
if (PRE_FIFO_SIZE == 0) begin
assign i_tdata_int = i_tdata;
assign i_tlast_int = i_tlast;
assign i_tvalid_int = i_tvalid;
assign i_tready = i_tready_int;
end else begin
for (n = 0; n < SIZE; n = n + 1) begin
axi_fifo #(.WIDTH(WIDTH+1), .SIZE(PRE_FIFO_SIZE)) axi_fifo (
.clk(clk), .reset(reset), .clear(clear),
.i_tdata({i_tlast[n],i_tdata[WIDTH*(n+1)-1:WIDTH*n]}), .i_tvalid(i_tvalid[n]), .i_tready(i_tready[n]),
.o_tdata({i_tlast_int[n],i_tdata_int[WIDTH*(n+1)-1:WIDTH*n]}), .o_tvalid(i_tvalid_int[n]), .o_tready(i_tready_int[n]),
.space(), .occupied());
end
end
endgenerate
// Make arrays for easier muxing
genvar i;
generate
for (i = 0; i < SIZE; i = i + 1) begin
assign i_tdata_arr[i] = i_tdata_int[WIDTH*(i+1)-1:WIDTH*i];
end
endgenerate
// Switch select line either immediately or after the last word in a packet
reg [$clog2(SIZE)-1:0] select_hold;
generate
if (SWITCH_ON_LAST) begin
reg init;
always @(posedge clk) begin
if (reset | clear) begin
init <= 1'b0;
select_hold <= 'd0;
end else begin
if (|i_tvalid) begin
init <= 1'b1;
end
// Set select any time after reset and before the first packet OR
// at the end of a packet
if (~init | (o_tlast_int & o_tvalid_int & o_tready_int)) begin
select_hold <= select;
end
end
end
end else begin
always @(*) begin
select_hold <= select;
end
end
endgenerate
// Mux
assign o_tdata_int = i_tdata_arr[select_hold];
assign o_tlast_int = i_tlast_int[select_hold];
assign o_tvalid_int = i_tvalid_int[select_hold];
assign i_tready_int = (1'b1 << select_hold) & {SIZE{o_tready_int}};
generate
if(POST_FIFO_SIZE == 0) begin
assign o_tdata = o_tdata_int;
assign o_tlast = o_tlast_int;
assign o_tvalid = o_tvalid_int;
assign o_tready_int = o_tready;
end else begin
axi_fifo #(.WIDTH(WIDTH+1),.SIZE(POST_FIFO_SIZE)) axi_fifo (
.clk(clk), .reset(reset), .clear(clear),
.i_tdata({o_tlast_int,o_tdata_int}), .i_tvalid(o_tvalid_int), .i_tready(o_tready_int),
.o_tdata({o_tlast,o_tdata}), .o_tvalid(o_tvalid), .o_tready(o_tready),
.space(), .occupied());
end
endgenerate
endmodule
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