01-02-2013, 12:23 PM
Introduction to Microprocessor
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Micro-Operations
A computer executes a program
Fetch/execute cycle
Each cycle has a number of steps
Called micro-operations
Each step does very little
Atomic operation of CPU
Types of Micro-operation
Transfer data between registers
Transfer data from register to external
Transfer data from external to register
Perform arithmetic or logical ops
Basic Elements of Processor
ALU
Registers
Internal data pahs
External data paths
Control Unit
Microprocessor (CPU)
Programmable integrated device (silicon chip) that has computing & decision making capabilities
Communicates & operates in binary numbers 0 & 1, called bits
Has a fixed set of instructions in the form of binary patterns – machine language
Difficult for humans to remember machine language – each instruction is represented using abbreviated names (mnemonics)
Registers
Memory Address Register (MAR)
Connected to address bus
Specifies address for read or write op
Memory Buffer Register (MBR)
Connected to data bus
Holds data to write or last data read
Program Counter (PC)
Holds address of next instruction to be fetched
Instruction Register (IR)
Holds last instruction fetched
Control Signals
Clock
One micro-instruction (or set of parallel micro-instructions) per clock cycle
Instruction register
Op-code for current instruction
Determines which micro-instructions are performed
Flags
State of CPU
Results of previous operations
From control bus
Interrupts
Acknowledgements
[attachment=49216]
Micro-Operations
A computer executes a program
Fetch/execute cycle
Each cycle has a number of steps
Called micro-operations
Each step does very little
Atomic operation of CPU
Types of Micro-operation
Transfer data between registers
Transfer data from register to external
Transfer data from external to register
Perform arithmetic or logical ops
Basic Elements of Processor
ALU
Registers
Internal data pahs
External data paths
Control Unit
Microprocessor (CPU)
Programmable integrated device (silicon chip) that has computing & decision making capabilities
Communicates & operates in binary numbers 0 & 1, called bits
Has a fixed set of instructions in the form of binary patterns – machine language
Difficult for humans to remember machine language – each instruction is represented using abbreviated names (mnemonics)
Registers
Memory Address Register (MAR)
Connected to address bus
Specifies address for read or write op
Memory Buffer Register (MBR)
Connected to data bus
Holds data to write or last data read
Program Counter (PC)
Holds address of next instruction to be fetched
Instruction Register (IR)
Holds last instruction fetched
Control Signals
Clock
One micro-instruction (or set of parallel micro-instructions) per clock cycle
Instruction register
Op-code for current instruction
Determines which micro-instructions are performed
Flags
State of CPU
Results of previous operations
From control bus
Interrupts
Acknowledgements