Enhance the 8-Bit CPU

Objective of this lab:

	To study the operation of a CPU and the control unit. 
	To enhance the ALU of the 8-bit CPU.

Preparation

	Read lab lecture notes.

Lab Assignments

1. Add OR operation to the 8-bit CPU that we have learned.

   
    	opcode# MNEMONIC                 DESCRIPTION
           ==============================================================
           00      XOR source, destination  XOR the contents of source,
                                            destination, and store the
                                            result in the destination
           --------------------------------------------------------------
           01      AND source, destination  AND the contents of source,
                                            destination, and store the
                                            result in the destination
           --------------------------------------------------------------
           10      NOT source, destination  invert the contents of
                                            source and store the result
                                            in destination
           --------------------------------------------------------------
           11      OR source, destination   OR the contents of source, 
   					 destination,  and store the 
   					 result in destination
           --------------------------------------------------------------
   
   
   

   Please note that the ALU will need two 8-bit operands input and produce the output of the ALU.
   Hand in a screen shot showing your new ALU in the 8-bit CPU circuit.

2. Implement the following tasks with your enhanced 8-bit CPU, remember to pre-load the registers or memory when needed:

   
   	1) Write out and hand in the microinstructions to perform this operation 
   	   XOR #5,(C) 
   	   including the machine code and how you load it to the memory.
   
   	   Pre-load the registers or memory when needed.
   	   For example:  Load 00001000  to the C register
        			 Load 00000000  to the memory location 8
   
   	2) Write out and hand in the microinstructions to perform the operation
   
   	   OR 5, 8
   	   including the machine code and how you load it to the memory.
   
   	   Pre-load the registers or memory when needed.
   	   For example:  Load 00000000  to the memory location 5
   			 Load 00001010  to the memory location 8
   
   	

Question (hand in your answer)

 
	   Describe how unconditional branches could be added to the CPU and 
	   what additional things this would require. 
	   Remember that a branch instruction uses an offset from the current 
	   location. 

	   Hand in your answer for this question.