Learn an 8-Bit CPU

Objective of this lab:

	To study the operation of an 8-bit CPU and control unit. 


	Read lab lecture notes and the material in this page.

Lab Assignments

  1. Obtain an 8-bit CPU working circuit file

    The circuit just obtained is a 8 bit version of the 1 bit CPU we built in last lab with a few additions:
    	To get a feel for the circuit before more details are examined, 
    	do the following: 
    	1.	load the number 8 into memory location 2 
    	2.	move (the contents in) memory location 2 to the PC 
    	3.	increment the PC 
          Write down the signals with the microinstructions to hand-in:
  2. Execute the program (Hand in)
    a).	Write out the equivalent assembly language mnemonics of the following 
    	machine language code:
          Location 	Contents 	Assembly Language Mnemonics 
          0 	10000001  
          1 	00010110  
          2 	00000101  
          3 	00001000  
    b). Load the preceding program (in machine code) to the memory. c). Pre-load value 1 in the B register, preload 0 in the memory location 8. Make sure the PC points to the beginning of the program. d). Write out the microinstructions necessary to execute the program. Hand in the procedures used in the different steps including the equivalent assembly language mnemonics and microinstructions needed to execute the program. ALSO remember to hand in the answers to the following two questions.

Questions (hand in the answers)

	1) Describe the purpose of the 3->8 decoder. 

	2) Describe how the RAM chip control signals are used to read 
	   and write to memory. 

Copyright: Department of Computer Science, University of Regina.