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

fix minor bug in first non preamble char parity check

Browse Source
This commit is contained in:
Arthur Lu 2022-08-28 22:23:07 +00:00
parent 90c683d1da
commit 155d18721f
2 changed files with 5 additions and 5 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

8
RTL/program3_tb.sv
View File

@ -24,7 +24,7 @@ module program3_tb () ;
// 53 characters in length // 53 characters in length
// *** No more than 24 leading space characters, including preamble. *** // *** No more than 24 leading space characters, including preamble. ***
// string str1 = // string str1 =
string str1 = " A joke is a very serious thing."; // sample program 1 input string str1 = " four score and seven years ago..."; // sample program 1 input
// string str1 = " Knowledge comes, but wisdom lingers. "; // alternative inputs // string str1 = " Knowledge comes, but wisdom lingers. "; // alternative inputs
// string str1 = " 01234546789abcdefghijklmnopqrstuvwxyz. "; // (make up your own, // string str1 = " 01234546789abcdefghijklmnopqrstuvwxyz. "; // (make up your own,
// string str1 = " A joke is a very serious thing."; // as well) // string str1 = " A joke is a very serious thing."; // as well)
@ -52,19 +52,19 @@ module program3_tb () ;
assign LFSR_ptrn[7] = 7'h7E; assign LFSR_ptrn[7] = 7'h7E;
assign LFSR_ptrn[8] = 7'h7B; assign LFSR_ptrn[8] = 7'h7B;
always_comb begin always_comb begin
pt_no = 0; //$random>>22; // or pick a specific one pt_no = $urandom_range(0, 8); //$random>>22; // or pick a specific one
if(pt_no>8) pt_no[3] = 1'b0; // restrict to 0 through 8 (our legal patterns) if(pt_no>8) pt_no[3] = 1'b0; // restrict to 0 through 8 (our legal patterns)
lfsr_ptrn = LFSR_ptrn[pt_no]; // engage the selected pattern lfsr_ptrn = LFSR_ptrn[pt_no]; // engage the selected pattern
end end
// now select a starting LFSR state -- any nonzero value will do // now select a starting LFSR state -- any nonzero value will do
always_comb begin always_comb begin
LFSR_init = 7'b1;//$random>>2; // or set a value, such as 7'b1, for debug LFSR_init = $urandom;//$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; if(!LFSR_init) LFSR_init = 7'b1; // prevents illegal starting state = 7'b0;
end end
// set preamble lengths for the program (always > 9 but < 16) // set preamble lengths for the program (always > 9 but < 16)
always_comb begin always_comb begin
pre_length = 10;//$random>>10 ; // program 1 run pre_length = $urandom_range(10, 15);//$random>>10 ; // program 1 run
if(pre_length < 10) pre_length = 10; // prevents pre_length < 10 if(pre_length < 10) pre_length = 10; // prevents pre_length < 10
if(pre_length > 15) pre_length = 15; if(pre_length > 15) pre_length = 15;
end end

2
firmware/program3.asm
View File

@ -91,7 +91,7 @@ finish_preamble: LDI lfsr_routine
JEZ r2 // jump to finish preamble loop if this plaintext == space(32) JEZ r2 // jump to finish preamble loop if this plaintext == space(32)
LDI correct_pre LDI correct_pre
PUT r2 // put correct handler address in r2 PUT r2 // put correct handler address in r2
RXR r1 // check r1 for errors RXR r3 // check r1 for errors
JEZ r2 JEZ r2
error_pre: LDI #x80 error_pre: LDI #x80
STW r12 STW r12