fix program 3 to have correct error detection,

added duplicate label syntax error check in assembler
This commit is contained in:
Arthur Lu 2022-08-20 03:14:36 +00:00
parent 9254063e3e
commit dd4f8ef9f8
3 changed files with 30 additions and 9 deletions

View File

@ -126,7 +126,7 @@ module program3_tb () ;
dut.DM.core[m+64] = msg_crypto1[m];
for(int n=24; n<64; n++) begin // load subsequent, possibly corrupt, encrypted message into data memory
// set flipper = 8 or higher to disable bit corruption
flipper = 8;//$random; // value between 0 and 63, inclusive
flipper = $random;//$random; // value between 0 and 63, inclusive
dut.DM.core[n+64] = msg_crypto1[n]^(1<<flipper);
if(flipper<8) flipped[n]=1;
end

View File

@ -119,6 +119,9 @@ for file in targets:
line = line.replace('\t', '') # remove leading tabs
line = line.replace('\n', '') # remove trailing newline
if ': ' in line:
if line.split(': ')[0] in labels:
print('dublicate label "' + line.split(': ')[0] + '" detected')
exit(1)
labels[line.split(': ')[0]] = index # ': ' must be used to end a label
no_comments.append(line.split(': ')[1])
else:

View File

@ -88,17 +88,35 @@ finish_preamble: LDI lfsr_routine
LDI #d32 // get value of space
SUB r1 // compare if r1 == 32
JEZ r2 // jump to finish preamble loop if this plaintext == space(32)
CLB r1 // clear leading bit of plaintext
GET r1 // get r1 to r0
STW r12 // store plaintext
NXT r12 // increment write only if we found the first non preamble char
LDI correct_pre
PUT r2 // put correct handler address in r2
CHK r1 // check r1 for errors
JEZ r2
error_pre: LDI #x80
STW r12
LDI common
JMP r0
correct_pre: CLB r1
GET r1
STW r12
common_pre: NXT r12 // increment write only if we found the first non preamble char
main_loop: LDI lfsr_routine // load address for the lfsr_routine label
JAL r0 // jump to the lfsr_routine label
LDW r11 // load the next ciphertext byte
PUT r1 // store ciphertext in r1
LDI correct
PUT r2 // load address of correct handler in r2
CHK r1 // check r1(ciphertext) for errors
JEZ r2 // if there are no errors, jump to correct handler, otherwise continue to error handler
error: LDI #x80
STW r12
LDI common
JMP r0
correct: GET r1 // retrieve ciphertext from r1
XOR r7 // bitwise XOR the current state with ciphertext space to generate plaintext
CLB r0 // clear the leading bit of the plaintext as in requirements
STW r12 // store plaintext to write pointer
NXT r11 // increment read pointer
common: NXT r11 // increment read pointer
NXT r12 // increment write pointer
LDI finish_post // load address of label done
NXT r9 // decrement number of remaining plaintext chars