Chapter 1 Flashcards
What is computer architecture?
a set of rules that defines the computer’s functionality, characterized by the ISA
What is ISA?
Instruction Set Architecture
What is the ISA concerned with?
Register set, instruction set, and addressing modes
ISA defines the…?
model of the computer from the programmer’s point of view
What embodies the computer’s ISA?
Its assembly language
What is computer organization?
Concerned with the implementation of a computer’s ISA
Computer organization is often referred to as…
Microarchitecture
“CPU” stands for what?
Central Processing Unit
What word is synonymous for the CPU?
Microprocessor
What type of memory do most modern CPUs have on-chip?
Cache memory
What is a “word”
A single piece of data
What are processor registers specified by?
The number of bits they contain (can be 32-bit wide or 64-bit wide typically)
What is the FUNDAMENTAL difference between a register and a word in memory?
There is no fundamental difference
What is the PRACTICAL difference between a register and word in memory?
Registers are located within the CPU
For a stored program computer, the CPU…
reads instructions from memory and carries out operations on input data and data in memory
For a stored program computer, both data and instructions are stored…
in the same memory system
For a stored program computer, memory is a bottleneck because
both instructions and data must be retrieved from the memory and then the final data is stored back in memory
What is the clock?
Essentially a series of pules (ONs and OFFs) used to sequence the events within the computer
A clock is defined in terms of its
Repetition rate (frequency) or width
The formula for a clock’s width is
WIDTH = 1 / (FREQUENCY)
1 us is
1 microsecond (1 / 1 000 000)
1 ns is
1 nanosecond (1 / 1 000 000 000)
Can a programmer determine the difference between encoded data and encoded instructions simply by looking at the bit pattern?
NO
The stored program concept is:
a program that will continuously point to an address in memory for instructions, then point to the next instruction, decode, execute, and repeat forever
For the stored program concept, the 3 main memory ports are:
- Address port (1-way)
- Data port (2-way)
- Control port (1-way)
What does RTL Notation mean?
Register Transfer Language Notation
In RTL Notation, [ ] (square brackets) represent what?
The contents of a memory location
In RTL Notation a backwards arrow represents
A data transfer
In RTL Notation, “=” (equals sign) represent what?
The contents of a memory location is equal to the RHS. Can be used as a variable assignment
Three Address Instructions take on the form of what?
Operation, Address1 (BOLDED), Address2, Address3
“Operation, Address1 (BOLDED), Address2, Address3” is the form of what kind of instructions?
Three Address Instructions
Two Address Instructions take on the form of what?
Operation, Address1 (BOLDED), Address2
“Operation, Address1 (BOLDED), Address2” is the form of what kind of instructions?
Two Address Instructions
What kind of instructions erase one of the original data elements?
Two Address Instructions
What is the Memory Hierarchy?
• Registers > Cache > DRAM > Hard Disk
What is the fastest memory type?
Registers
What is faster: registers or cache?
Registers
What is faster: cache or DRAM?
Cache
What is the Memory Hierarchy ratio?
1 : 2^18 : 2^28 : 2^35
What is a Bus in essence?
A link between two or more functional parts of a computer
What is the difference between an Internal Bus and an External Bus?
An Internal Bus is located within the CPU or the motherboard while an External Bus can be a USB or FireWire
A USB is an example of what kind of bus?
External Bus
What is Bus Width?
the number of parallel data paths OR the number of wires that make up a bus
What is Bus Bandwidth?
the rate in which data can be transferred across the bus (bytes or bits per second)
What is Bus Latency?
the waiting period between a data transfer request and its completion
What is a constant?
a value that DOES NOT change during execution
What is a variable?
a value that CAN change during execution
what is a symbolic name?
a name given to a constant or a variable
What is a pointer?
a variable whose value is an address
What is an address?
a specific value that corresponds to a location in memory
