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Published in Phillip A. Laplante, Dictionary of Computer Science, Engineering, and Technology, 2017
indexed addressing an addressing mode in which an index value is added to a base address to determine the location (effective address) of an operand or instruction in memory. Typically, the base address designates the beginning location of a data structure in memory such as a table or array and the index value indicates a particular location in the structure.
Parallel Architectures
Published in Pranabananda Chakraborty, Computer Organisation and Architecture, 2020
Vector processors may be of different types, and consequently they follow different instruction formats. However, generic vector instructions are mostly composed of the following fields: Operation Code: The operation code must be specified to describe as to what type of operation the instruction intends to do, so that the respective functional unit can be allocated or the multifunctional unit can be reconfigured to perform the specified operation as indicated by this field. Normally, the microcode control is used to assign the needed resources.Base Address: For a memory-reference instruction, the base address is needed to find the beginning of the actual physical memory address for both source operands as well as result vectors. However, if the operands and results of the computation are located in vector register file (collection of registers), then the designated vector registers must be specified within the instruction format.Offset (or Displacement): The offset field contains the address which is relative to the prescribed base address. Using the given base address and the content of this offset field (positive or negative), the effective memory address of the operand vector is obtained after required computation.Address Increment: The address increment between the scalar elements of vector operand needs to be specified. Some vector computers, like the supercomputer Star-100 introduced by Control Data Corporation (CDC) in 1973, however, assume this increment to always be 1, i.e., they insist the elements to be consecutively stored in memory all the time. Other computers like TI-ASC allow a variable increment while storing the scalar elements of vector operands. This approach certainly offers a greater flexibility at the time of allocating memory to an application.Vector Length: The vector length (a positive integer) is always needed, that declares the number of elements present in a vector operand in the form of an ordered set. This is required to assert the end of vector instruction execution.
Microcontroller Software
Published in Syed R. Rizvi, Microcontroller Programming, 2016
An algorithm may be loosely defined as a set of instructions for solving a problem. In other words, it is an effective method for solving a problem expressed as a finite sequence of steps. Proficiency with algorithms is of strategic value in using the computer as a problem-solving tool, since a computer can solve a problem only after it has been told how to solve it. This means that human effort is required to develop detailed solution procedures that can subsequently be communicated to the computer for implementation. A solution is said to be computer implemented when instructions have been prepared that enable the computer to carry out the procedure. These instructions must be communicated to the computer in a language that it can “understand.” Such a language is often referred to as a programming language. A hierarchy diagram of computer programming languages relative to the computer hardware is shown in Figure 4.1. At the lowest level is the computer hardware (CPU, memory, disk drive, input/output). Next is the machine language that the hardware understands because it is written with 1s and 0s. Recall from Chapter 2 that high and low levels were denoted by 1s and 0s. Machine code is commonly referred to as object code, and a machine code program is referred to as an object code program. The machine code consists of the following: Operational code (opcodes): An opcode is a unique multibit code given to identify each instruction to the microcontroller.Operands (data): The parameters that follow the assembly language mnemonic to complete the specification of the instruction. An operand is data that is operated upon by the instruction. For example, an addition instruction adds operands, and a load instruction reads an operand from an address in memory and loads it into a processor register. The operand field is defined as a group of up to three bytes following the opcode.Addresses of the operands: An address is a pointer into memory. Each memory location has a unique address by which it is identified. An address is an identifier for a memory location, at which a computer program or a hardware device can store data and later retrieve it. An absolute address is a complete address, whereas an offset is a value that is added to a base address to reference another memory location.
Named data networking with neural networks for intelligent image processing information systems
Published in Enterprise Information Systems, 2022
Zhengzhou Han, Zhuo Li, Kaihua Liu, Liu Yan
The output unit deploys a Bitmap structure to obtain the actual memory index address. Among them, the Bitmap is divided into several parts, and each slot records the order in which the name data is inserted into the part to realise the dynamic memory allocation of the actual storage unit. By multiplying the predicted CDF value of the model unit by the total number of slots in the Bitmap, the mapping slot position in the Bitmap can be obtained. Finally, the actual memory index address can be obtained according to the base address corresponding to the part where the slot is located, and the address offset represented by the serial number in the slot.