alu/cse141L-project
Archived
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

add program2 testbench

Browse Source
This commit is contained in:
Arthur Lu 2022-08-17 18:01:09 -07:00
parent 7344df39d8
commit 9a8c9a3771
1 changed files with 156 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

156
RTL/program2_tb.sv Normal file
View File

@ -0,0 +1,156 @@
// program2_tb
// testbench for programmable message decryption (Program #2)
// CSE141L
// runs program 2 (decrypt a message)
module program2_tb () ;
// DUT interface -- four one-bit wires, three to DUT, one from
bit clk , // advances simulation step-by-step
init = 1'b1 , // init (reset) command to DUT
start = 1'b1 ; // req (start program) command to DUT
wire done ; // done flag returned by DUT
// test bench parameters
bit [3:0] pre_length ; // space char. bytes before first char. in message
bit [7:0] message1[54] , // original raw message, in binary
msg_padded1[64], // original message, plus pre- and post-padding w/ ASCII spaces
msg_crypto1[64]; // encrypted message according to the DUT
bit [6:0] lfsr_ptrn , // chosen one of 9 maximal length 7-tap shift reg. ptrns
LFSR_ptrn[9] , // the 9 candidate maximal-length 7-bit LFSR tap ptrns
lfsr1[64] , // states of program 1 encrypting LFSR
LFSR_init ; // one of 127 possible NONZERO starting states
int score ; // count of correct encyrpted characters
// our original American Standard Code for Information Interchange message follows
// note in practice your design should be able to handle ANY ASCII string that is
// restricted to characters between space (0x20) and script f (0x9f) and shorter than
// 55 characters in length
string str1 = "Mr. Watson, come here. I want to see you."; // sample program 1 input
// string str1 = " Knowledge comes, but wisdom lingers. "; // alternative inputs
// string str1 = " 01234546789abcdefghijklmnopqrstuvwxyz. "; // (make up your own,
// string str1 = " f A joke is a very serious thing."; // as well)
// string str1 = " Ajok "; //
// string str1 = "@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@";
// string str1 = " Knowledge comes, but wisdom lingers. "; //
// displayed encrypted string will go here:
string str_enc1[64]; // program 1 desired output will go here
int strlen; // incoming string length
int pt_no; // select LFSR pattern, value 0 through 8
int file_no; // write to file
// the 8 possible maximal-length feedback tap patterns from which to choose
assign LFSR_ptrn[0] = 7'h60; // 110_0000
assign LFSR_ptrn[1] = 7'h48;
assign LFSR_ptrn[2] = 7'h78;
assign LFSR_ptrn[3] = 7'h72;
assign LFSR_ptrn[4] = 7'h6A;
assign LFSR_ptrn[5] = 7'h69;
assign LFSR_ptrn[6] = 7'h5C;
assign LFSR_ptrn[7] = 7'h7E;
assign LFSR_ptrn[8] = 7'h7B;
always_comb begin
pt_no = 0; //$random>>22; // or pick a specific one
if(pt_no>8) pt_no[3] = 0; // restrict to 0 through 8 (our legal patterns)
lfsr_ptrn = LFSR_ptrn[pt_no]; // engage the selected pattern
end
// now select a starting LFSR state -- any nonzero value will do
always_comb begin
LFSR_init = 'b1;//$random>>2; // or set a value, such as 7'b1, for debug
if(!LFSR_init) LFSR_init = 7'b1; // prevents illegal starting state = 7'b0;
end
// set preamble lengths for the four program runs (always > 9 but < 16)
always_comb begin
pre_length = 10;//$random>>10 ; // program 1 run
if(pre_length < 10) pre_length = 10; // prevents pre_length < 10
else if(pre_length > 26) pre_length = 26;
end
// ***** instantiate your own top level design here *****
top_level dut(
.clk (clk ), // input: use your own port names, if different
.init (init ), // input: some prefer to call this ".reset"
.req (start), // input: launch program
.ack (done ) // output: "program run complete"
);
initial begin
//***** pre-load your instruction ROM here or inside itself *****
// $readmemb("encoder.bin", dut.instr_rom.rom);
// you may also pre-load desired constants, etc. into
// your data_mem here -- the upper addresses are reserved for your use
// dut.data_mem.DM[128]=8'hfe; //whatever constants you want
// to display to console, change this line to file_no = 'b1;
file_no = 'b1;
// file_no = $fopen("msg_decoder_out.txt"); // create your output file
#0ns strlen = str1.len; // length of string 1 (# characters between " ")
if(strlen>52) strlen = 52; // clip message at 52 characters
// program 1 -- precompute encrypted message
lfsr1[0] = LFSR_init; // any nonzero value (zero may be helpful for debug)
$fdisplay(file_no,"run encryption program; original message = ");
$fdisplay(file_no,"%s",str1); // print original message in transcript window
$fdisplay(file_no,"LFSR_ptrn = 0x%h, LFSR_init = 0x%h",lfsr_ptrn,LFSR_init);
$fdisplay(file_no,"pt_no = %d",pt_no);
// will subtract 0x20 from each preamble and message character
for(int j=0; j<64; j++) // pre-fill message_padded with ASCII space characters
msg_padded1[j] = 8'h20; //
for(int l=0; l<strlen; l++) // overwrite up to 49 of these spaces w/ message itself
msg_padded1[pre_length+l] = str1[l]; //
// compute the LFSR sequence
for (int ii=0;ii<63;ii++)
lfsr1[ii+1] = {(lfsr1[ii][5:0]),(^(lfsr1[ii]&lfsr_ptrn))};
// encrypt the message charater-by-character, then prepend the parity
// testbench will change on falling clocks to avoid race conditions at rising clocks
for (int i=0; i<64; i++) begin
msg_crypto1[i] = (msg_padded1[i] ^ lfsr1[i]);
msg_crypto1[i][7] = ^msg_crypto1[i][6:0]; // prepend parity bit into MSB
$fdisplay(file_no,"i=%d, msg_pad=0x%h, lfsr=%b msg_crypt w/ parity = 0x%h",
i,msg_padded1[i],lfsr1[i],msg_crypto1[i]);
// for display purposes only, add 8'h20 to avoid nonprintable characters (<8'h20)
str_enc1[i] = string'(msg_crypto1[i][6:0]+8'h20);
end
$fdisplay(file_no,"encrypted string = ");
for(int jj=0; jj<64; jj++)
$fwrite(file_no,"%s",(str_enc1[jj]));
$fdisplay(file_no,"\n");
// run encryption program first to know what to decrypt
// ***** load operands into your data memory *****
// ***** use your instance name for data memory and its internal core *****
// for(int m=0; m<61; m++)
// dut.DM.core[m] = 8'h20; // pad memory w/ ASCII space characters
// for(int m=0; m<strlen; m++)
// dut.DM.core[m] = str1[m]; // overwrite/copy original string into device's data memory[0:strlen-1]
// dut.DM.core[61] = pre_length; // number of bytes preceding message
// dut.DM.core[62] = lfsr_ptrn; // LFSR feedback tap positions (9 possible ptrns)
// dut.DM.core[63] = LFSR_init; // LFSR starting state (nonzero)
for(int n=0; n<64; n++) // load encrypted message into data memory
dut.DM.core[n+64] = msg_crypto1[n];
#20ns init = 1'b0; // suggestion: reset = 1 forces your program counter to 0
#10ns start = 1'b0; // request/start = 1 holds your program counter
#60ns; // wait for 6 clock cycles of nominal 10ns each
wait(done); // wait for DUT's ack/done flag to go high
#10ns $fdisplay(file_no,"");
$fdisplay(file_no,"program 2:");
// ***** reads your results and compares to test bench
// ***** use your instance name for data memory and its internal core *****
for(int n=0; n<64; n++) begin
if(msg_padded1[n]==dut.DM.core[n]) begin
$fdisplay(file_no,"%d bench msg: %s %h dut msg: %h",
n, msg_padded1[n], msg_padded1[n], dut.DM.core[n]);
score++;
end
else
$fdisplay(file_no,"%d bench msg: %s %h dut msg: %h OOPS!",
n, msg_padded1[n], msg_padded1[n], dut.DM.core[n]);
end
$fdisplay(file_no,"score = %d/64",score);
#20ns $fclose(file_no);
#20ns $stop;
end
always begin // continuous loop
#5ns clk = 1; // clock tick
#5ns clk = 0; // clock tock
end
endmodule