I have finished the assignment.
Please, download the zip file containing modified files from here:http://ge.tt/api/1/files/2qSR23i1/0/blob?download
The modified files are:
Sim.emi = microprogram file that contains the DJNZ modification
Microprogram-mod1.doc = updated microcode "listing", added DJNZ microcode
Instructionset-mod1.doc = updated instruction set, updated DJNZ instruction
DJNZ-test.txt = assembler code for testing DJNZ op-code
Microprogram assignment description.doc = document containing the description of how the DJNZ microcode works (as well as the list of "desirable op-codes" as per assignment brief).
You can inspect the Sim.emi by opening it with Mip.exe.
You can run the DJNZ-test.txt by opening it with Mic1.exe.
Please check it out and let me know if there are any issues.
P.S. It took me almost four hours to figure out the microcode, how to use Mip.exe, Mic1.exe, how to define DJNZ mnemonic, write the DJNZ microcode (that was the easy part), add it to existing microcode, test it and write the description. I realize that this may seem long but I had to start from scratch. Hopefully this does not exceeds you budget too much. :)