Computer Architecture
Faculty of Computer Science & Engineering - HCMUT
Chapter 4: The Processor
Binh Tran-Thanh
thanhbinh@hcmut.edu.vn
This chapter contents
▪The basic units in the CPU
▪Functions of the major components in the CPU
▪Instruction execution at hardware level
▪Performance and trace off among CPUs
This chapter outcomes
Students who complete this course will be
able to:
▪Explain the structure of a computer system
and deeply understand how it works at the
hardware level.
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Introduction
▪CPU performance factors
▪Instruction count
▪Determined by ISA and compiler
▪CPI and Cycle time
▪Determined by CPU hardware
▪We will examine two MIPS implementations
▪A simplified version (single clock cycle)
▪A more realistic pipelined version
▪Simple subset, shows most aspects
▪Memory reference: lw, sw
▪Arithmetic/logical: add, sub, and, or, slt
▪Control transfer: beq, j
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The simplified processor.
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Sign
extend
Shift
left 2
Address
Write
data
pc Read
address
Instruction
[31–0]
Instruction
memory
Instruction [25–21]
Instruction [20–16]
Instruction [15–11]
Instruction [15–0]
Instruction [31–26]
Register
s
ALU
control
ALU
Data
memor
y
0
M
u
x
1
Control
Add
0
M
u
x
1
1
M
u
x
0
RegDst
Branch
MemRead
MemtoReg
ALUOp
MemWrite
ALUSrc
RegWrite
ALU
result
0
M
u
x
1
Zero
ALU
result
Read
register 1
Read
register 2
Write
Register
Write
data
Read
data 1
Read
data 2
4
16 32
Read
data
Instruction [5–0]
Add