I have the main module with FIFO stuff.
Here it is:
module syn_fifo #(
parameter DATA_WIDTH = 8, // inpit capacity
parameter DATA_DEPTH = 8 // the depth of the FIFO
)
(
input wire clk,
input wire rst,
// Write_______________________________________________
input wire [DATA_WIDTH-1:0]din, // the input data
input wire wren, // Write anable
output wire full,
// Read________________________________________________
output wire [DATA_WIDTH-1:0]dout, // The output data
input wire rden, // Read enable
output wire empty
);
integer q_size; // The queue size(length)
integer golova; // The queue beginning
integer hvost; // The end of queue
reg [DATA_WIDTH-1:0]fifo[DATA_DEPTH-1:0];
assign full = (q_size == DATA_DEPTH) ? 1'b1: 1'b0; // FIFO is full
/*
True { full = (q_size==DATA_TEPTH) = 1 }, then wire "full" goes to "1" value
False { full = (q_size==DATA_TEPTH) = 0 }, then wire "full" goes to "0" value
*/
assign empty = (golova == hvost); // FIFO is empty
assign dout = fifo[hvost]; // FWFT (other write mode)
integer i;
//___________(The queue fullness)___________________
always @(posedge clk or posedge rst)
begin
if (rst == 1'b1)
begin
for (i = 0; i < DATA_DEPTH; i = i + 1) // incrementing the FIFO
fifo[i] <= 0; // Resetting the FIFO
golova <= 0; // Resetting the queue start variable
end
else
begin //Write_______________________________________
if (wren && ~full)
begin
fifo[golova] <= din; // putting data in to the golova
if (golova == DATA_DEPTH-1) // restrictions for the queue beginning
golova <= 0; // Reset the beginning
else
golova <= golova + 1; // other occurence incrementing
end
end
end
//Reading
always @(posedge clk or posedge rst)
begin
if (rst == 1'b1)
begin
hvost <= 0;
end
else
begin
if (rden && !empty)
/*for staying inside the queue limits - make the check of non equality of the "hvost" & "queue size"*/
begin
if (hvost == DATA_DEPTH-1) // if hvost = DATA_DEPTH-1, then
hvost <= 0; // Reset hvost
else
hvost <= hvost + 1;
end
end
end
always @ (posedge clk)
begin
if (rst == 1'b1) begin
q_size <= 0;
end
else
begin
case ({wren && ~full, rden && ~empty} )
2'b01: q_size <= q_size + 1; // RO
2'b10: q_size <= q_size - 1; // WO
default: q_size <= q_size; // read and write at the same time
endcase
end
end
endmodule
Also i've got the testbench module down delow:
`timescale 1ns / 1ps
module fifo_tb();
localparam CLK_PERIOD = 10;
reg clk;
reg rst;
always begin
clk <= 1'b0;
#(CLK_PERIOD / 2);
clk <= 1'b1;
#(CLK_PERIOD / 2);
end
localparam DATA_WIDTH = 8;
localparam DATA_DEPTH = 4;
reg [DATA_WIDTH-1:0]din;
reg wren;
reg rden;
wire [DATA_WIDTH-1:0]dout;
wire empty;
wire full;
wire wr_valid;
wire rd_valid;
task write;
input integer length;
begin
if (length) begin
@(posedge clk);
wren <= 1'b1;
while (length) begin
@(posedge clk);
if (wr_valid) begin
length <= length - 1;
if (length == 1) begin
wren <= 1'b0;
end
end
end
end
end
endtask
task read;
input integer length;
begin
if (length) begin
@(posedge clk);
rden <= 1'b1;
while (length) begin
@(posedge clk);
if (rd_valid) begin
length <= length - 1;
if (length == 1) begin
rden <= 1'b0;
end
end
end
end
end
endtask
initial begin
rst <= 1'b0;
wren <= 1'b0;
rden <= 1'b0;
#50;
rst <= 1'b1;
#50;
rst <= 1'b0;
#200;
/* Test Start */
//write(4);
//read(4);
/* Test Stop */
#1000;
$finish;
end
assign wr_valid = wren & ~full;
assign rd_valid = rden & ~empty;
always @(posedge clk) begin
if (rst == 1'b1) begin
din <= 0;
end else begin
if (wr_valid == 1'b1) begin
din <= din + 1;
end
end
end
// write?
always begin
#400;
write(5);
#15;
write(7);
#25;
write(3);
#15;
write(9);
#15;
write(1);
#10000;
end
// read?
always begin
#420;
read(3);
#37;
read(13);
#21;
read(7);
#15;
read(9);
#15;
read(4);
#20;
read(7);
#10000;
end
initial begin
$dumpfile("test.vcd");
$dumpvars(0,fifo_tb);
end
syn_fifo #(.DATA_WIDTH(DATA_WIDTH),
.DATA_DEPTH(DATA_DEPTH)) dut ( .clk(clk),
.rst(rst),
.din(din),
.wren(wren),
.full(full),
.dout(dout),
.rden(rden),
.empty(empty));
endmodule
Trying to compile all of it with iVerilog + GTKwave + Win10 by next command:
C:\Program Files\iverilog\bin>iverilog -o fifo.v fifo_tb.v
The compiler gives me the next message:
fifo_tb.v:138:error: Unknown module type:syn_fifo
2 error(s) during elaboration.
These modules were missing:syn_fifo referenced 1 times
At the necessary line "138" maybe the main mistake is covered by the "Number sign" in module instantiation?
/*132|*/ initial begin
/*133|*/ $dumpfile("test.vcd");
/*134|*/ $dumpvars(0,fifo_tb);
/*135|*/ end
/*136|*/
/*137|*/ syn_fifo #(.DATA_WIDTH(DATA_WIDTH),
/*138|*/ .DATA_DEPTH(DATA_DEPTH)) dut ( .clk(clk),
/*139|*/ .rst(rst),
/*140|*/ .din(din),
/*141|*/ .wren(wren),
/*142|*/ .full(full),
/*143|*/ .dout(dout),
/*144|*/ .rden(rden),
/*145|*/ .empty(empty));
/*146|*/
/*147|*/ endmodule
I'm not shure of that.
