程序代写代做代考 assembly computer architecture mips Microsoft PowerPoint – CSE220 Unit01 Introduction to Digital Systems.pptx
Microsoft PowerPoint – CSE220 Unit01 Introduction to Digital Systems.pptx
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1Kevin McDonnell Stony Brook University – CSE 220
CSE 220:
Systems Fundamentals I
Unit 1:
Introduction to Digital
Systems
2Kevin McDonnell Stony Brook University – CSE 220
The Landscape of Computing
• Three broad classes of modern computing devices:
• Personal computers: general-purpose, low-performing
machines
• Servers and supercomputers: more powerful
machines usually built for a particular purpose
• Modern supercomputers typically have 10,000+
processing units and terabytes of memory
• Embedded computers: special-purpose computers that
are embedded in a larger system, such as a car, TV,
network router, etc.
• For which of these computing platforms will fault tolerance
be the least? (i.e., for which computer type is a failure
totally unacceptable?)
3Kevin McDonnell Stony Brook University – CSE 220
But Wait, There’s More!
• Harder to categorize are devices like smart phones and
tablets
• Somewhere between a personal computer and an
embedded system? Or a totally different category?
• Cloud computing systems also don’t fit well into these
categories
• An evolution of server technology
• SaaS: software as a service – why buy an expensive
server when you can rent one at a fraction of the price?
4Kevin McDonnell Stony Brook University – CSE 220
Architecture vs. Organization
• The terms computer architecture and computer
organization are often thrown about without clear
explanation of what these terms mean
• Computer architecture refers to those aspects of the
hardware that are visible to the programmer
• e.g., instructions the computer is capable of executing,
word size (native unit of data of CPU), data formats
• Computer organization (also called microarchitecture)
refers to how the physical components of the machine
interact to implement the architecture
• A particular computer architecture could be
implemented by several different microarchitectures
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5Kevin McDonnell Stony Brook University – CSE 220
Eight Great Ideas in Architecture
1. Design for Moore’s Law
• Moore’s “Law” refers to the trend that
circuit complexity/speed doubles
every 18-24 months
• Anticipate where technology will be
when a system is completed, not when
it is being designed
2. Use abstraction to simplify design
• Abstraction refers to ignoring irrelevant
details and focusing on higher-level
design/implementation issues
• Part of software development too
6Kevin McDonnell Stony Brook University – CSE 220
Eight Great Ideas in Architecture
3. Make the common case fast
• Enhance the performance of those operations which
occur most frequently
4. Increase performance via parallelism
• Perform operations in parallel (simultaneously) when
possible
5. Increase performance via pipelining
• A form of parallelism in which single instructions are
broken into multiple stages and executed in parallel
6. Increase performance via prediction
• The computer “guesses” which operation will be
executed next and starts executing it early
7Kevin McDonnell Stony Brook University – CSE 220
Eight Great Ideas in Architecture
7. Implement a hierarchy of memories
• Fastest, smallest and expensive memory at the top;
slowest, largest and cheapest at the bottom
8. Increase dependability via redundancy
• Include redundant components that can take over when
a failure occurs
• Of particular importance in cloud computing systems
and other server technologies
8Kevin McDonnell Stony Brook University – CSE 220
The Three Y’s
1. Hierarchy
• We will look at the design of a CPU from the bottom-up
as a collection of collaborating modules
2. Modularity
• These modules have well-defined functions and
interfaces
3. Regularity
• Modules can be reused many times in a single design,
thereby reducing then umber of distinct components
that must be designed
• Note how well these concepts apply also to software design
and implementation
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9Kevin McDonnell Stony Brook University – CSE 220
von Neumann Architecture
• The term von Neumann architecture refers to a
particular computer hardware design model for a stored-
program digital computer (e.g., PCs)
• Separate central processing unit (CPU) and random-
access memory (RAM)
• Both instructions and data stored in RAM
• Data to be processed is transferred from RAM to CPU, and
results are transferred back to RAM
• Named for Hungarian-American mathematician John von
Neumann, but others participated in the original design
• Most modern computers follow this basic design model,
but are substantially more complex
10Kevin McDonnell Stony Brook University – CSE 220
von Neumann Architecture
• CPU: performs the actual processing
• control unit: performs instruction decoding and control
• arithmetic/logic unit (ALU): performs basic
arithmetical and logical operations
• registers: small amount of memory used to hold
addresses, instructions and data
• RAM: larger memory used to store both program
instructions and data
• I/O devices permit data to enter/leave machine
• We’ll concern ourselves with standard input, standard
output, standard error and also file I/O
11Kevin McDonnell Stony Brook University – CSE 220
Stored-program Computer
• In a stored-program computer, the program to be executed
is stored in RAM along with the data to be processed
• So please note: by saying “stored program” it does NOT
mean we are storing the programs on a disk
• A program consists of binary instructions stored in RAM
• Each instruction or small piece of data in RAM has an
associated memory address to indicate its location
• A program counter (or instruction pointer) register in
the CPU stores the memory address of the next instruction
to be executed
• Earlier computers were “hard-wired” to a particular
program via switches, patch cables, etc.
12Kevin McDonnell Stony Brook University – CSE 220
Fetch/Decode/Execute Cycle
• So what is a 3 GHz CPU doing 3 billion times per second?
• The basic cycle of operation of a von Neumann-style
computer:
• Fetch: the next instruction is retrieved from RAM
• Decode: the instruction is examined to determine what
the CPU should do:
• Opcode: field that determines the type of instruction
• Operand(s): fields that determine the source and
destination of data to be operated on
• Execute: the operation specified by the instruction is
performed, which may involve one or more memory
references
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13Kevin McDonnell Stony Brook University – CSE 220
Fetch/Decode/Execute Cycle
14Kevin McDonnell Stony Brook University – CSE 220
Instruction Set
• The instruction set of a computer is the repertoire of
instructions that the CPU can perform
• Determined by the computer architects/designers
• “Hard-wired” as part of the computer design
• Different for each type of CPU
• What is an “instruction”?
• Answer: it depends on the kind of CPU
• In RISC (reduced instruction set computer) CPUs, the
instruction set is small and consists of simple instructions
• In CISC (complex instruction set computer) CPUs, the
instruction set is larger and consists of instructions that
vary in length and complexity
15Kevin McDonnell Stony Brook University – CSE 220
Typical RISC Instructions
• In this course we will study the MIPS architecture
(Microprocessor without Interlocked Pipeline Stages),
which is of the RISC type. Instructions include:
• Load data from memory to CPU register
• Copy (“Store”) data from CPU register to memory
• Add, subtract, multiply, divide, etc. data in CPU
registers
• AND, OR, XOR, NOT, etc. data in CPU registers
• Shift and rotate data in CPU registers
• Jump based on CPU state flags (“condition codes”)
• Call a subroutine (function) and return to caller
16Kevin McDonnell Stony Brook University – CSE 220
Example
• A high-level programming language statement like
X = A + B would be translated to assembly language
instructions as follows:
• LOAD A
• LOAD B
• ADD C, A, B
• STORE C, X
• Naturally, the real assembly instructions are a little more
sophisticated than this (e.g., from what memory address
are loading the data?), but the beauty of RISC machines is
that the instructions are quite simple
• The assembly language instructions are then translated
into machine language (1s and 0s) for execution by the CPU
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17Kevin McDonnell Stony Brook University – CSE 220
Course Roadmap
• Data representations: numbers, characters
• MIPS assembly programming: basics, conditionals, loops
• MIPS assembly programming: functions, 1D arrays
• Digital logic design: basic circuit design
• Digital logic design: computational units, timing
• Digital logic design: circuit simplification
• MIPS assembly programming: 2D arrays
• MIPS architecture: single-cycle data path
• MIPS assembly programming: recursive functions
• MIPS architecture: multi-cycle data path
• MIPS architecture: pipelined data path
