OA Flashcards
superscalar
Technique primarily associated with hardware.
Functional units (ALU, Floating Point Unit, Load/Store Unit) are duplicated in the pipeline of a superscalar processor which allows the hardware to issue multiple instructions to each unit simultaneously.
LEGv8 doubleword
Another natural unit of access in a computer, usually a group of 64 bits (8 bytes); corresponds to the size of a register in the LEGv8 architecture
virtual memory
A technique that uses main memory as a “cache” for secondary storage
The address is broken into a virtual page number and a page offset
Program counter (PC)
The register that contains the address of the next instruction to be executed
LDUR
load register
Register File
A state element that consists of a set of registers that can be read and written by supplying a register number to be accessed.
provides 1024 scalar 32-bit registers for up to 64 threads.
machine language
The language made up of binary-coded instructions that is used directly by the computer
system software
The set of programs that enables a computer’s hardware devices and application software to work together; it includes the operating system and utility programs.
operating system
(computer science) software that controls the execution of computer programs and may provide various services
Assembly Language
Programming language that has the same structure and set of commands as machine languages but allows programmers to use symbolic representations of numeric machine code.
IBM 360/91
Introduced many new concepts, including dynamic detection of memory hazards, generalized forwarding, and reservation stations. Tomasulo’s algorithm
The internal organization of the 360/91 shares many features with the Pentium III and Pentium 4, as well as with several other microprocessors. One major difference was that there was no branch prediction in the 360/91 and hence no speculation. Another major difference was that there was no commit unit, so once the instructions finished execution, they updated the registers.
Dynamic Random Access Memory (DRAM)
Memory built as an integrated circuit; it provides random access to any location. Access times are 50 nanoseconds and cost per gigabyte in 2012 was $5 to $10.
Multiple DRAMs are used together to contain the instructions and data of a program. In contrast to sequential access memories, such as magnetic tapes, the RAM portion of the term DRAM means that memory accesses take basically the same amount of time no matter what portion of the memory is read.
Modern DRAMS consist of rows in each bank
frame buffering
A portion of RAM containing a bitmap that drives a video display. It is a memory buffer containing a complete frame of data.
The image to be represented onscreen is stored in the frame buffer, and the bit pattern per pixel is read out to the graphics display at the refresh rate. The animation below shows a frame buffer with a simplified design of just 4 bits per pixel.
Datapath
The component of the processor that performs arithmetic operations
Control
The component of the processor that commands the datapath, memory, and I/O devices according to the instructions of the program.
Integrated circuit
Also called a chip. A device combining dozens to millions of transistors.
Central processor unit (CPU)
Also called processor. The active part of the computer, which contains the datapath and control and which adds numbers, tests numbers, signals I/O devices to activate, and so on.
Static random access memory (SRAM)
Also memory built as an integrated circuit, but faster and less dense than DRAM.
Instruction set architecture
Also called architecture. An abstract interface between the hardware and the lowest-level software that encompasses all the information necessary to write a machine language program that will run correctly, including instructions, registers, memory access, I/O, and so on.
Application binary interface (ABI)
The user portion of the instruction set plus the operating system interfaces used by application programmers. It defines a standard for binary portability across computers.
Volatile memory
Storage, such as DRAM, that retains data only if it is receiving power.
Nonvolatile Memory
A form of memory that retains data even in the absence of a power source and that is used to store programs between runs. A DVD disk is nonvolatile.
Magnetic disk
Also called hard disk. A form of nonvolatile secondary memory composed of rotating platters coated with a magnetic recording material. Because they are rotating mechanical devices, access times are about 5 to 20 milliseconds and cost per gigabyte in 2012 was $0.05 to $0.10
Main memory
Also called primary memory. Memory used to hold programs while they are running; typically consists of DRAM in today’s computers.