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|
`timescale 1ns/1ps
`define NS_PER_TICK 1
`define NUM_TEST_CASES 7
`include "sim_exec_report.vh"
`include "sim_clks_rsts.vh"
`include "sim_axis_lib.svh"
module axi_packet_gate_tb();
`TEST_BENCH_INIT("axi_packet_gate_tb", `NUM_TEST_CASES, `NS_PER_TICK);
localparam CLK_PERIOD = $ceil(1e9/166.67e6);
`DEFINE_CLK(clk, CLK_PERIOD, 50);
`DEFINE_RESET(reset, 0, 100);
localparam MAX_PKT_SIZE = 64;
// +1 for terror
axis_master #(.DWIDTH(32+1)) m_axis (.clk(clk));
axis_slave #(.DWIDTH(32)) s_axis (.clk(clk));
axi_packet_gate #(
.WIDTH(32),
.SIZE($clog2(MAX_PKT_SIZE)),
.USE_AS_BUFF(1)
) dut (
.clk(clk), .reset(reset), .clear(1'b0),
.i_tdata(m_axis.axis.tdata[31:0]),
.i_tvalid(m_axis.axis.tvalid),
.i_tlast(m_axis.axis.tlast),
.i_terror(m_axis.axis.tdata[32]), // Use MSB as terror
.i_tready(m_axis.axis.tready),
.o_tdata(s_axis.axis.tdata),
.o_tvalid(s_axis.axis.tvalid),
.o_tlast(s_axis.axis.tlast),
.o_tready(s_axis.axis.tready)
);
/********************************************************
** Verification
********************************************************/
task random_wait(int unsigned min_cycles, int unsigned max_cycles);
begin
int unsigned num_cycles;
do begin
num_cycles = $random() & (2**($clog2(max_cycles))-1);
end while ((num_cycles < min_cycles) || (num_cycles > max_cycles));
if (num_cycles != 0) begin
for (int unsigned i = 0; i < num_cycles; i++) begin
@(posedge clk);
end
@(negedge clk); // Realign with negedge
end
end
endtask
initial begin : tb_main
string s;
logic error, last;
int cnt, check;
/********************************************************
** Test 1 -- Reset
********************************************************/
`TEST_CASE_START("Wait for Reset");
m_axis.reset();
s_axis.reset();
while (reset) @(posedge clk);
`TEST_CASE_DONE(~reset);
/********************************************************
** Test 2 -- Fill / Empty FIFO
********************************************************/
`TEST_CASE_START("Fill and empty FIFO");
error = 0;
last = 0;
cnt = 0;
$display("Write %0d words to FIFO", MAX_PKT_SIZE);
for (int i = 0; i < MAX_PKT_SIZE; i++) begin
$sformat(s, "FIFO prematurely full at %0d (tready not asserted!)", i);
`ASSERT_FATAL(m_axis.axis.tready, s);
m_axis.push_word({error,cnt}, i == MAX_PKT_SIZE-1);
cnt++;
end
$display("Done writing to FIFO");
if (m_axis.axis.tready) begin
$display("FIFO not full, fill remaining space");
// Continue filling until FIFO is full
while (m_axis.axis.tready) begin
m_axis.push_word({error,cnt}, 0);
cnt++;
end
$display("Done filling remaining space");
$display("Expected FIFO size: %0d, Actual: %0d",MAX_PKT_SIZE,cnt);
end
// On the first packet, output is held off until a full packet is received
repeat(MAX_PKT_SIZE) @(posedge clk);
$display("Empty FIFO and check output");
for (int i = 0; i < cnt; i++) begin
$sformat(s, "FIFO prematurely empty at %0d (tvalid not asserted!)", i);
`ASSERT_FATAL(s_axis.axis.tvalid, s);
s_axis.pull_word(check, last);
$sformat(s, "FIFO output incorrect! Expected: %0d, Actual: %0d", i, check);
`ASSERT_FATAL(check == i, s);
if (i == cnt-1) begin
`ASSERT_FATAL(last, "tlast not asserted on final word!");
end else begin
`ASSERT_FATAL(~last, "tlast asserted prematurely!");
end
end
`TEST_CASE_DONE(1);
/********************************************************
** Test 3 -- Check gating
********************************************************/
`TEST_CASE_START("Check gating");
error = 0;
last = 0;
cnt = 0;
$display("Write %0d words to FIFO and check out valid", MAX_PKT_SIZE);
for (int i = 0; i < MAX_PKT_SIZE/2; i++) begin
m_axis.push_word({error,cnt}, 0);
cnt++;
end
// On the first packet, output is held off until a full packet is received
repeat(10) @(posedge clk);
`ASSERT_FATAL(~s_axis.axis.tvalid, "Saw output before a full packet input");
for (int i = MAX_PKT_SIZE/2; i < MAX_PKT_SIZE; i++) begin
m_axis.push_word({error,cnt}, i == MAX_PKT_SIZE-1);
cnt++;
end
repeat(10) @(posedge clk);
`ASSERT_FATAL(s_axis.axis.tvalid, "Did not see output even after full packet input");
$display("Empty FIFO and check output");
for (int i = 0; i < cnt; i++) begin
$sformat(s, "FIFO prematurely empty at %0d (tvalid not asserted!)", i);
`ASSERT_FATAL(s_axis.axis.tvalid, s);
s_axis.pull_word(check, last);
$sformat(s, "FIFO output incorrect! Expected: %0d, Actual: %0d", i, check);
`ASSERT_FATAL(check == i, s);
if (i == cnt-1) begin
`ASSERT_FATAL(last, "tlast not asserted on final word!");
end else begin
`ASSERT_FATAL(~last, "tlast asserted prematurely!");
end
end
`TEST_CASE_DONE(1);
/********************************************************
** Test 4 -- Ensure no bleed
********************************************************/
`TEST_CASE_START("Ensure no bleed");
error = 0;
last = 0;
cnt = 0;
$display("Write %0d words to FIFO (full packet)", MAX_PKT_SIZE/2);
for (int i = 0; i < MAX_PKT_SIZE/2; i++) begin
m_axis.push_word({error,cnt}, i == (MAX_PKT_SIZE/2)-1);
cnt++;
end
$display("Write %0d words to FIFO (partial packet)", MAX_PKT_SIZE/4);
for (int i = 0; i < MAX_PKT_SIZE/4; i++) begin
m_axis.push_word({error,cnt}, 0);
cnt++;
end
// On the first packet, output is held off until a full packet is received
repeat(10) @(posedge clk);
for (int i = 0; i < MAX_PKT_SIZE/2; i++) begin
$sformat(s, "FIFO prematurely empty at %0d (tvalid not asserted!)", i);
`ASSERT_FATAL(s_axis.axis.tvalid, s);
s_axis.pull_word(check, last);
$sformat(s, "FIFO output incorrect! Expected: %0d, Actual: %0d", i, check);
`ASSERT_FATAL(check == i, s);
if (i == (MAX_PKT_SIZE/2)-1) begin
`ASSERT_FATAL(last, "tlast not asserted on final word!");
end else begin
`ASSERT_FATAL(~last, "tlast asserted prematurely!");
end
end
repeat(10) @(posedge clk);
`ASSERT_FATAL(~s_axis.axis.tvalid, "Partial packet bled through with full packet");
for (int i = MAX_PKT_SIZE/4; i < MAX_PKT_SIZE/2; i++) begin
m_axis.push_word({error,cnt}, i == (MAX_PKT_SIZE/2)-1);
cnt++;
end
repeat(10) @(posedge clk);
`ASSERT_FATAL(s_axis.axis.tvalid, "Did not see output even after full packet input");
$display("Empty FIFO and check output");
for (int i = MAX_PKT_SIZE/2; i < cnt; i++) begin
$sformat(s, "FIFO prematurely empty at %0d (tvalid not asserted!)", i);
`ASSERT_FATAL(s_axis.axis.tvalid, s);
s_axis.pull_word(check, last);
$sformat(s, "FIFO output incorrect! Expected: %0d, Actual: %0d", i, check);
`ASSERT_FATAL(check == i, s);
if (i == cnt-1) begin
`ASSERT_FATAL(last, "tlast not asserted on final word!");
end else begin
`ASSERT_FATAL(~last, "tlast asserted prematurely!");
end
end
`TEST_CASE_DONE(1);
/********************************************************
** Test 5 -- Back to back small packets
********************************************************/
`TEST_CASE_START("Back to back small packets");
error = 0;
last = 0;
cnt = 0;
for (int i = 0; i < MAX_PKT_SIZE/2; i++) begin
$sformat(s, "FIFO prematurely full at %0d (tready not asserted!)", i);
`ASSERT_FATAL(m_axis.axis.tready, s);
m_axis.push_word({error,cnt}, i == MAX_PKT_SIZE/2-1);
cnt++;
end
for (int i = 0; i < MAX_PKT_SIZE/2; i++) begin
$sformat(s, "FIFO prematurely full at %0d (tready not asserted!)", i);
`ASSERT_FATAL(m_axis.axis.tready, s);
m_axis.push_word({error,cnt}, i == MAX_PKT_SIZE/2-1);
cnt++;
end
fork
begin
for (int k = 0; k < 8; k++) begin
for (int i = 0; i < MAX_PKT_SIZE/2; i++) begin
m_axis.push_word({error,cnt}, i == MAX_PKT_SIZE/2-1);
cnt++;
end
end
end
begin
@(posedge clk);
@(posedge clk);
@(posedge clk);
for (int k = 0; k < 10; k++) begin
for (int i = 0; i < MAX_PKT_SIZE/2; i++) begin
`ASSERT_FATAL(s_axis.axis.tvalid, "tvalid not asserted!");
s_axis.pull_word(check, last);
$sformat(s, "FIFO output incorrect! Expected: %0d, Actual: %0d", i, check);
`ASSERT_FATAL(check == (i+k*MAX_PKT_SIZE/2), s);
if (i == MAX_PKT_SIZE/2-1) begin
`ASSERT_FATAL(last, "tlast not asserted on final word!");
end else begin
`ASSERT_FATAL(~last, "tlast asserted prematurely!");
end
end
end
end
join
`TEST_CASE_DONE(1);
#2000; // Delay to make the tests visually distinct in waveform viewer
/********************************************************
** Test 6 -- Drop error packet
** - Send packet, drop a packet, send another packet
********************************************************/
`TEST_CASE_START("Drop error packet");
cnt = 0;
$display("Write packet with %0d words to FIFO", MAX_PKT_SIZE/4);
error = 0;
for (int i = 0; i < MAX_PKT_SIZE/4; i++) begin
$sformat(s, "FIFO prematurely full at %0d (tready not asserted!)", i);
`ASSERT_FATAL(m_axis.axis.tready, s);
m_axis.push_word({error,cnt}, i == MAX_PKT_SIZE/4-1);
cnt++;
end
$display("Write error packet with %0d words to FIFO", MAX_PKT_SIZE/4);
error = 1;
for (int i = 0; i < MAX_PKT_SIZE/4; i++) begin
$sformat(s, "FIFO prematurely full at %0d (tready not asserted!)", i);
`ASSERT_FATAL(m_axis.axis.tready, s);
m_axis.push_word({error,cnt}, i == MAX_PKT_SIZE/4-1);
cnt++;
end
$display("Write packet with %0d words to FIFO", MAX_PKT_SIZE/4);
error = 0;
for (int i = 0; i < MAX_PKT_SIZE/4; i++) begin
$sformat(s, "FIFO prematurely full at %0d (tready not asserted!)", i);
`ASSERT_FATAL(m_axis.axis.tready, s);
m_axis.push_word({error,cnt}, i == MAX_PKT_SIZE/4-1);
cnt++;
end
for (int i = 0; i < MAX_PKT_SIZE/4; i++) begin
$sformat(s, "FIFO prematurely empty at %0d (tvalid not asserted!)", i);
`ASSERT_FATAL(s_axis.axis.tvalid, s);
s_axis.pull_word(check, last);
$sformat(s, "FIFO output incorrect! Expected: %0d, Actual: %0d", i, check);
`ASSERT_FATAL(check == i, s);
if (i == MAX_PKT_SIZE/4-1) begin
`ASSERT_FATAL(last, "tlast not asserted on final word!");
end else begin
`ASSERT_FATAL(~last, "tlast asserted prematurely!");
end
end
for (int i = 0; i < MAX_PKT_SIZE/4; i++) begin
$sformat(s, "FIFO prematurely empty at %0d (tvalid not asserted!)", i);
`ASSERT_FATAL(s_axis.axis.tvalid, s);
s_axis.pull_word(check, last);
$sformat(s, "FIFO output incorrect! Expected: %0d, Actual: %0d", i, check);
`ASSERT_FATAL(check == (i+MAX_PKT_SIZE/2), s);
if (i == MAX_PKT_SIZE/4-1) begin
`ASSERT_FATAL(last, "tlast not asserted on final word!");
end else begin
`ASSERT_FATAL(~last, "tlast asserted prematurely!");
end
end
`TEST_CASE_DONE(1);
#2000;
/********************************************************
** Test 7 -- Random read / writes
********************************************************/
`TEST_CASE_START("Random read / writes");
error = 0;
last = 0;
cnt = 0;
fork
begin
for (int k = 1; k <= 5000*MAX_PKT_SIZE; k++) begin
m_axis.push_word({error,k}, (k % 16) == 0);
random_wait(0,16);
end
end
begin
for (int k = 1; k <= 5000*MAX_PKT_SIZE; k++) begin
random_wait(0,16);
s_axis.pull_word(check, last);
$sformat(s, "FIFO output incorrect! Expected: %0d, Actual: %0d", k, check);
`ASSERT_FATAL(check == k, s);
if ((k % 16) == 0) begin
`ASSERT_FATAL(last, "tlast not asserted!");
end else begin
`ASSERT_FATAL(~last, "tlast asserted prematurely!");
end
end
end
join
`TEST_CASE_DONE(1);
`TEST_BENCH_DONE;
end
endmodule
|
