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Machine Instruction Charactersitic - Coggle Diagram
Machine Instruction Charactersitic
Instruction set design
very complex
Fundamental design issue
Data types
Instruction format
Registers
Operation repertoire
Addressing
Areas where source and result operands located
I/O device
Processor register
Main or virtual memory
Immediate
Instruction representation
Opcodes(mnemonics)
MUL - multiply
DIV- divide
SUB - subtract
LOAD- load data from memory
ADD - add
STOR - store data to memory
operands
Types
Characters
ASCII code
save in computer in binary form
Logical Data
n-bit unit consist
Advantage of bit-oriented view
manipulate the bits of a data item
shift significant bits if floating -point operation
convert from IRA to packed decimal, extract the rightmost 4 bits of each byte
Addresses (Register & memory)
Numbers
stored is limited
limit to magnitude of number (size of data)
limit to precision in terms of floating point
Type numerical data
Binary floating point
Decimal
Binary integer or binary fixed point
Packed Decimal (BCD)
represented by a 4-bit code with 2 digit stored per byte
Instruction types
Control
Test
Branch
Data movement
I/O instruction
Data processing
Arithmetic
logic (Boolean)
Data storage (movement data into/ out of the memory)
Types of operations
Logical
Conversion
change the format or operate on the format of data
Arithmetic
other possible operation
Negate
Increment
Absolute
Decrement
Transfer of control
reason of use
skip
branch
Data transfer
Must specify
location of source and destination operands
length of data
mode of addressing
I/O
approaches
Isolated programmed I/O
Memory-mapped programmed I/O
I/O processor
DMA
addressing mode
Indirect
Register
EA = R
Direct
Effective address(EA) = address field (A)
required only one memory reference
register indirect
Immediate addressing
Advantage
No memory reference , saving one memory
simplest form (Operand = A)
Di
Dispalcement
Relative
base-register
Indexing
Stack
Last-in-First-Out