To study the operation of an 8-bit CPU and control unit.
Read lab lecture notes and the material in this page.
~ftp/pub/class/301/ftp/8bitcpu.cct
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: ________________________________ ________________________________ ________________________________ ________________________________
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.
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.