Lab1 : CPU sim
Lab2 : Memory Extended Chips Using
Proteus Simulator
Lab 1: CPU Sim
Objectives :
1 - To create a new machine on CPU Sim with a given
set of specifications in a correct way
2- To create an instruction set on a simulated machine
on CPU Sim in a correct way
3- To write an assembly language program using a
given instruction set on a given machine on CPU Sim
in a correct way
• The main points should be revised for Lab
- A program consist of some instructions , each
instruction consist of some microinstructions
which is the atomic operation of a CPU.
- instruction is executed in two cycles :
(Fetch cycle ) and ( execute cycle)
Fetch cycle : fetch instruction from memory to
instruction register .
Execute cycle : execute the instruction in IR .
Fetch cycle
MAR
PC
MBR
IR
Mem
C.U
Fetch Microinstructions :
T1
T2
T3
T4
T5
-
MAR
IR (Address field)
MDR
(Memory)
IR
(MDR)
PC
PC + 1
decode – ir
Execute Cycle example
LOAD microinstructions :
MAR
MDR
ACC
LOAD
IR (Address field)
(Memory)
(MDR)
Address field
MAR
ACC
MBR
Mem
1. construct Hardware modules :
2. set registers and main memory
3. setting the
microinstructions required
4. design the microinstruction that transfer data
between registers
5. Design the microinstruction that transfer data
between registers and memory
6. Design the microinstruction that increment the
PC with 2 because memory is byte addressable
7. Design the microinstruction that decode the IR
registers
8. Design fetch sequence
9. Design jmpz instruction: jump if last Arithmetic
operation is zero
10. Design the microinstructions of Jmpz
Lab2: Memory Extended Chips Using
Proteus Simulator
Objectives:
- learn how to use Proteus simulation
to simulate memory using chip 7489
Tools:
- Proteus version 7.4
- Memory chips 16 X 4 bit “No 7489”
- 7 SEG display
1. Fetch 7489 memory chips from pick devices
2. The basic memory chip connection