//-----------------------------------------------------------------------------
// SoC Labs Basic SHA-2 ID Buffer Testbench
// A joint work commissioned on behalf of SoC Labs, under Arm Academic Access license.
//
// Contributors
//
// David Mapstone (d.a.mapstone@soton.ac.uk)
//
// Copyright 2022, SoC Labs (www.soclabs.org)
//-----------------------------------------------------------------------------
`timescale 1ns/1ns
`include "sha256_id_buf.sv"
module tb_sha256_id_buf;
logic clk;
logic nrst;
logic en;
logic sync_rst;
// ID Buffer IN
logic [5:0] id_in;
logic id_in_last;
logic id_in_valid;
logic id_in_ready;
// ID Out
logic [5:0] id_out;
logic id_out_last;
logic id_out_valid;
logic id_out_ready;
// Status Out - Gets updated after every hash
logic [5:0] status_id;
sha256_id_buf uut (
.clk (clk),
.nrst (nrst),
.en (en),
.sync_rst (sync_rst),
// ID IN
.id_in (id_in),
.id_in_last (id_in_last),
.id_in_valid (id_in_valid),
.id_in_ready (id_in_ready),
// ID Out
.id_out (id_out),
.id_out_last (id_out_last),
.id_out_valid (id_out_valid),
.id_out_ready (id_out_ready),
// Status Out - Gets updated on every output Handshake
.status_id (status_id)
);
logic id_in_drive_en;
logic id_out_drive_ready;
logic [5:0] id_in_queue [$];
logic id_in_last_queue [$];
int id_in_gap_queue [$];
logic id_in_wait_queue;
logic [5:0] id_out_queue [$];
logic [5:0] status_id_out_queue [$];
logic id_out_last_queue [$];
int id_out_stall_queue [$];
logic id_out_wait_queue;
// TODO: Handle Status Checking
// Handle Valid and Data for id_in
always_ff @(posedge clk, negedge nrst) begin: id_in_valid_drive
if (!nrst) begin
id_in <= 6'd0;
id_in_valid <= 1'b0;
id_in_last <= 1'b0;
id_in_gap <= 0;
id_in_wait_queue <= 1'b1;
end else if (id_in_drive_en) begin
if (id_in_gap > 1) begin
id_in_gap <= id_in_gap - 1;
id_in_valid <= 1'b0;
end else begin
id_in_valid <= 1'b1;
end
if (((id_in_valid == 1'b1) && (id_in_ready == 1'b1)) ||
(id_in_wait_queue == 1'b1)) begin
// Data transfer just completed or transfers already up to date
if ((id_in_queue.size() > 0) && (id_in_last_queue.size() > 0) && (id_in_gap_queue.size() > 0)) begin
id_in <= id_in_queue.pop_front();
id_in_last <= id_in_last_queue.pop_front();
if (id_in_gap_queue[0] == 0) begin
id_in_valid <= 1'b1;
end else begin
id_in_valid <= 1'b0;
end
id_in_gap <= id_in_gap_queue.pop_front();
id_in_wait_queue <= 1'b0;
end else begin
// No data currently avaiable in queue to write but transfers up to date
id_in_wait_queue <= 1'b1;
id_in_valid <= 1'b0;
end
end
end
end
logic [5:0] id_out_check;
logic [5:0] status_id_out_check;
logic id_out_last_check;
int id_in_gap;
int id_out_stall;
int packet_num;
// Handle Output Ready Signal Verification
always @(posedge clk) begin
// Check Override Control on Ready
if (id_out_drive_ready) begin
// Count down to zero before enabling Ready
if (id_out_stall > 1) begin
id_out_stall <= id_out_stall - 1;
id_out_ready <= 1'b0;
end else begin
// Wait for handshake before updating stall value
if ((id_out_valid == 1'b1) && (id_out_ready == 1'b1)) begin
if (id_out_stall_queue.size() > 0) begin
if (id_out_stall_queue[0] == 0) begin
id_out_ready <= 1'b1;
end else begin
id_out_ready <= 1'b0;
end
id_out_stall <= id_out_stall_queue.pop_front();
end
// Keep Ready Asserted until handshake seen
end else begin
id_out_ready <= 1'b1;
end
end
end else begin
id_out_ready <= 1'b0;
end
end
// Handle Output Data Verification
always @(posedge clk) begin
// Check Data on Handshake
if ((id_out_valid == 1'b1) && (id_out_ready == 1'b1)) begin
// Check Size
assert (id_out == id_out_check) else begin
$error("id_out missmatch! packet %d | recieve: %x != check: %x", packet_num, id_out, id_out_check);
$finish;
end
if ($test$plusargs ("DEBUG")) $display("id_out match! packet %d | recieve: %x == check: %x", packet_num, id_out, id_out_check);
// Check Last Flag
assert (id_out_last == id_out_last_check) else begin
$error("id_out_last missmatch! packet %d | recieve: %x != check: %x", packet_num, id_out_last, id_out_last_check);
$finish;
end
if ($test$plusargs ("DEBUG")) $display("id_out_last match! packet %d | recieve: %x == check: %x", packet_num, id_out_last, id_out_last_check);
// Check Status Value
assert (status_id == status_id_out_check) else begin
$error("id_out_last missmatch! packet %d | recieve: %x != check: %x", packet_num, status_id, status_id_out_check);
$finish;
end
if ($test$plusargs ("DEBUG")) $display("status_id match! packet %d | recieve: %x == check: %x", packet_num, status_id, status_id_out_check);
// Pop new values
if ((id_out_queue.size() > 0) && (status_id_out_queue.size() > 0) && (id_out_last_queue.size() > 0)) begin
id_out_check <= id_out_queue.pop_front();
status_id_out_check <= status_id_out_queue.pop_front();
id_out_last_check <= id_out_last_queue.pop_front();
if (id_out_last_check == 1'b1) begin
packet_num <= packet_num + 1;
end
end else begin
$display("Test Passes");
$finish;
end
end
end
// File Reading Variables
int fd; // File descriptor Handle
logic [5:0] temp_id_in; // Temporary Input Data Storage
logic temp_id_in_last; // Temporary Input Data Last
int temp_id_in_gap; // Temporary Input Gap
logic [5:0] temp_id_out; // Temporary ID Value
logic [5:0] temp_status_id_out; // Temporary Status ID Value
logic temp_id_out_last; // Temporary ID last;
int temp_id_out_stall; // Temporary ID stall;
initial begin
$dumpfile("sha256_id_buf.vcd");
$dumpvars(0, tb_sha256_id_buf);
id_in_drive_en = 0;
id_out_drive_ready = 0;
// Read input data into Queue in
fd = $fopen("../stimulus/testbench/input_buf_id_stim.csv", "r");
while ($fscanf (fd, "%d,%b,%d", temp_id_in, temp_id_in_last, temp_id_in_gap) == 3) begin
id_in_queue.push_back(temp_id_in);
id_in_last_queue.push_back(temp_id_in_last);
id_in_gap_queue.push_back(temp_id_in_gap);
end
$fclose(fd);
// Read output data into Queue
fd = $fopen("../stimulus/testbench/output_buf_id_ref.csv", "r");
while ($fscanf (fd, "%d,%b,%d,%d", temp_id_out, temp_id_out_last, temp_status_id_out, temp_id_out_stall) == 4) begin
id_out_queue.push_back(temp_id_out);
id_out_last_queue.push_back(temp_id_out_last);
status_id_out_queue.push_back(temp_status_id_out);
id_out_stall_queue.push_back(temp_id_out_stall);
end
$fclose(fd);
// Initialise First Checking Values
id_out_check = id_out_queue.pop_front();
status_id_out_check = status_id_out_queue.pop_front();
id_out_last_check = id_out_last_queue.pop_front();
id_out_stall = id_out_stall_queue.pop_front();
// Defaultly enable Message Builder
en = 1;
// Defaultly set Sync Reset Low
sync_rst = 0;
#20 nrst = 1;
#20 nrst = 0;
#20 nrst = 1;
// Write some data into the config register
# 30 id_in_drive_en = 1;
# 30 id_out_drive_ready = 1;
end
initial begin
forever begin
#10 clk = 0;
#10 clk = 1;
end
end
endmodule