Computer Organization & Architecture

Pre-requisites, Topics and outcomes

Pre-requisites: Data structures and Algorithms, Computer Fundamentals and C

I taught this course to CSE, B.Tech. at IIT Jodhpur in the sessions: 2012-13, 2013-14, 2014-14

Digital Logic and Digital Systems

Topics:

• Overview and history of computer architecture
• Combinational vs. sequential logic/Field programmable gate arrays as a fundamental combinational & sequential logic building block
• Multiple representations/layers of interpretation (hardware is just another layer)
• Computer-aided design tools that process hardware and architectural representations
• Register transfer notation/Hardware Description Language (Verilog/VHDL)
• Physical constraints (gate delays, fan-in, fan-out, energy/power)

Course outcomes:

1. Describe the progression of computer technology components from vacuum tubes to VLSI, from mainframe computer architectures to the organization of warehouse-scale computers. [Familiarity].
2. Comprehend the trend of modern computer architectures towards multi-core and that parallelism is inherent in all hardware systems. [Familiarity]
3. Explain the implications of the “power wall” in terms of further processor performance improvements and the drive towards harnessing parallelism. [Familiarity]
4. Articulate that there are many equivalent representations of computer functionality, including logical expressions and gates, and be able to use mathematical expressions to describe the functions of simple combinational and sequential circuits. [Familiarity]
5. Design the basic building blocks of a computer: arithmetic-logic unit (gate-level), registers (gate-level), central processing unit (register transfer-level), memory (register transfer-level). [Usage]

Presentation Slides

Machine Level Representation of Data

Topics:

• Bits, bytes, and words
• Numeric data representation and number bases
• Fixed- and floating-point systems
• Signed and twos-complement representations
• Representation of non-numeric data (character codes, graphical data)
• Representation of records and arrays

Course outcomes:

1. Explain why everything is data, including instructions, in computers. [Familiarity]
2. Explain the reasons for using alternative formats to represent numerical data. [Familiarity]
3. Describe how negative integers are stored in sign-magnitude and twos-complement representations. [Familiarity]
4. Explain how fixed-length number representations affect accuracy and precision. [Familiarity]
5. Describe the internal representation of non-numeric data, such as characters, strings, records, and arrays. [Familiarity]
6. Convert numerical data from one format to another. [Usage]
7. Write simple programs at the assembly/machine level for string processing and manipulation. [Usage]

Presentation Slides

Assembly Level Machine Organization

Topics:

• Basic organization of the von Neumann machine
• Control unit; instruction fetch, decode, and execution
• Instruction sets and types (data manipulation, control, I/O)
• Assembly/machine language programming
• Instruction formats
• Addressing modes
• Subroutine call and return mechanisms (cross-reference PL/Language Translation and Execution)
• I/O and interrupts
• Heap vs. Static vs. Stack vs. Code segments
• Shared memory multiprocessors/multi-core organization
• Introduction to SIMD vs. MIMD and the Flynn Taxonomy

Course Outcomes:

1. Explain the organization of the classical von Neumann machine and its major functional units. [Familiarity]
2. Describe how an instruction is executed in a classical von Neumann machine, with extensions for threads, multiprocessor synchronization, and SIMD execution. [Familiarity]
3. Describe instruction level parallelism and hazards, and how they are managed in typical processor pipelines. [Familiarity]
4. Summarize how instructions are represented at both the machine level and in the context of a symbolic assembler. [Familiarity]
5. Demonstrate how to map between high-level language patterns into assembly/machine language notations. [Familiarity]
6. Explain different instruction formats, such as addresses per instruction and variable length vs. fixed length formats. [Familiarity]
7. Explain how subroutine calls are handled at the assembly level. [Familiarity]
8. Explain the basic concepts of interrupts and I/O operations. [Familiarity]
9. Write simple assembly language program segments. [Usage]
10. Show how fundamental high-level programming constructs are implemented at the machine-language level. [Usage]

Presentation Slides

Memory System Organization and Architecture

Topics:

• Storage systems and their technology
• Memory hierarchy: importance of temporal and spatial locality
• Main memory organization and operations
• Latency, cycle time, bandwidth, and interleaving
• Cache memories (address mapping, block size, replacement and store policy)
• Multiprocessor cache consistency/Using the memory system for inter-core synchronization/atomic memory operations
• Virtual memory (page table, TLB)
• Fault handling and reliability
• Error coding, data compression, and data integrity (cross-reference SF/Reliability through Redundancy)

Course Outcomes:

1. Identify the main types of memory technology (e.g., SRAM, DRAM, Flash, magnetic disk) and their relative cost and performance. [Familiarity]
2. Explain the effect of memory latency on running time. [Familiarity]
Describe how the use of memory hierarchy (cache, virtual memory) is used to reduce the effective memory latency. [Familiarity]
3. Describe the principles of memory management. [Familiarity]
4. Explain the workings of a system with virtual memory management. [Familiarity]
5. Compute Average Memory Access Time under a variety of cache and memory configurations and mixes of instruction and data references. [Usage]

Presentation Slides

Interfacing and Communication

Topics:

• I/O fundamentals: handshaking, buffering, programmed I/O, interrupt-driven I/O
• External storage, physical organization, and drives
• Interrupt structures: vectored and prioritized, interrupt acknowledgment
• Buses: bus protocols, arbitration, direct-memory access (DMA)
• Introduction to networks: communications networks as another layer of remote access
• Multimedia support
• RAID architectures

Course Outcomes:

1. Explain how interrupts are used to implement I/O control and data transfers. [Familiarity]
2. Identify various types of buses in a computer system. [Familiarity]
3. Describe data access from a magnetic disk drive. [Familiarity]
4. Compare common network organizations, such as ethernet/bus, ring, switched vs. routed. [Familiarity]
5. Identify the cross-layer interfaces needed for multimedia access and presentation, from image fetch from remote storage, through transport over a communications network, to staging into local memory, and final presentation to a graphical display. [Familiarity]
6. Describe the advantages and limitations of RAID architectures. [Familiarity]

Presentation Slides

Functional Organization

Topics:

• Implementation of simple datapaths, including instruction pipelining, hazard detection and resolution
• Control unit: hardwired realization vs. microprogrammed realization
• Instruction pipelining
• Introduction to instruction-level parallelism (ILP)

Course Outcomes

1. Compare alternative implementation of datapaths. [Familiarity]
2. Discuss the concept of control points and the generation of control signals using hardwired or microprogrammed implementations. [Familiarity]
3. Explain basic instruction level parallelism using pipelining and the major hazards that may occur. [Familiarity]
4. Design and implement a complete processor, including datapath and control. [Usage]
5. Determine, for a given processor and memory system implementation, the average cycles per instruction. [Assessment]

Multiprocessing and Alternative Architectures

Topics:

• Power Law
• Example SIMD and MIMD instruction sets and architectures
• Interconnection networks (hypercube, shuffle-exchange, mesh, crossbar)
• Shared multiprocessor memory systems and memory consistency
• Multiprocessor cache coherence

Course Outcomes:

1. Discuss the concept of parallel processing beyond the classical von Neumann model. [Familiarity]
2. Describe alternative parallel architectures such as SIMD and MIMD. [Familiarity]
3. Explain the concept of interconnection networks and characterize different approaches. [Familiarity]
4. Discuss the special concerns that multiprocessing systems present with respect to memory management and
5. describe how these are addressed. [Familiarity]
6. Describe the differences between memory backplane, processor memory interconnect, and remote memory via networks, their implications for access latency and impact on program performance. [Familiarity]