DLXSIM Assignment



To Do


  1. Copy the file ~reese/EE4713/copy_test.s to your local directory. You can execute this file in dlxsim by doing:
    % dlxsim
    (dlxsim) load copy_test.s
    (dlxsim) go _main
    (dlxsim) quit
    
    
    Execute it and see what it does.
  2. The '_main' function prints out two strings, 'string1' and 'string2' before and after the 'bcopy (byte-copy) subroutine . The 'bcopy' routine is called with the starting address of 'string1' in register 'r2', and the starting address of 'string2' in register 'r3'.
  3. You are to modify the 'bcopy' subroutine so that 'string1' is copied over 'string2'. You can tell when you have reached the end of 'string1' because it will have a byte value equal to zero. You can look at problem 3.8 in the textbook for a hint on how to write 'bcopy' but beware: this problem has some errors in it and it copies WORDS, not BYTES.

To Hand In