General purpose register Such a system enables the 'machine' to carry out data operations faster and effectively as the access to memory is reduced for temporary data storage. The ra register (r31) holds the return address used by procedure calls and is implicitly accessed by the call, callr and ret instructions. General-purpose register D. Learn about the different types of registers, such as data, address, control, floating-point, and vector registers, and see examples of architectures and CPUs that use them. Figure 12-2. The upper registers are used by the Bus Interface Unit for memory accesses, while the general-purpose lower registers are used by the Execution Unit. Before trying to understand some special purpose registers, let us try to understand the difference between General purpose and special purpose registers. Current System/390 systems use 64–bit Apr 13, 2023 · Hi all, I'm using s32 IDE for programming MPC5744p microcontroller. General Purpose registers: General purpose registers are additional registers in the processors that are capable of storing both data as well as addresses. But some have a specific intended purpose. General-purpose registers CPU registers can be placed into two categories: general-purpose and special-purpose. CR8 is used to prioritize external interrupts and is referred to as the task-priority register (TPR). There are different kinds of registers utilized for different reasons. General-purpose registers are flexible and can be utilized by the processor for a variety of tasks, such as holding temporary data and intermediate results of computations. These include the Program Counter (PC), Stack Pointer (SP), and Flag Registers. Also referred as: general purpose working registers, register file, general purpose register file. General-purpose register architectures are the most widely accepted models for computers today. Usages of the general purpose registers When the CPU excutes an instruction, the CPU may need to fetch the input operands for that instruction. The %rbp register has a special purpose: it points to the bottom of the current function’s stack frame, and local variables are often accessed relative to its value. How can I store the value of a register directly to a memory address using assembly code?? 4 days ago · The thirty-two 32-bit or 64-bit General Purpose Registers are numbered R0 through R31. 8086 has eight general purpose registers. Instruction Register ( IR ). 64-bit x86 has additional registers. The AMD64 architecture allows software to define up to 15 external interrupt-priority classes. Memory cell: The memory cell is a storage unit within the CPU that stores data and instructions. Trusted by parents, students, and Assembly 1: Basics Registers Registers are the fastest kind of memory available in the machine. General-Purpose Registers Eight 32-bit general-purpose registers (e. PIC16F877 (Perepheral Interphase Controller) Tutorial which covers Register Memory organisation and types of registers like General purpose,Special Function and Status registers,Option and INTCON registers. ) and is a register that doesn't have a special purpose. The memory address register (MAR) is a special-purpose register. As shown in the figure, each register is also assigned a data memory address, mapping them directly into the first 32 locations of the user data space. The 8086 microprocessor has byte and word-sized registers, but the 80386 contains double-word sized or extended registers. There is a separate set of 32 registers used for floating point and vector operations. ARM processors have both banked and unbanked registers. Mar 12, 2001 · Registers in assembly language programmingtable of contents for assembly language section register set accumulators data registers address registers general purpose registers constant registers floating point registers index registers base registers control registers program counter (location counter) processor flags result flags control flags stack pointer subroutine return pointer The Nios II architecture provides thirty-two 32-bit general-purpose registers, r0 through r31. A special purpose register is one that has a specific control or data handling task to carry out. Study with Quizlet and memorize flashcards containing terms like (True/False) Any 32-bit general-purpose register can be used as an indirect operand. Note: The implicit use of a register to resolve a symbol to a base and displacement does not create a reference in the General Purpose Register Cross Reference. com Apr 10, 2016 · According to Intel, in x64, the following registers are called general-purpose registers (RAX, RBX, RCX, RDX, RBP, RSI, RDI, RSP and R8-R15). While all modes always share the same physical registers for the first eight general-purpose registers (GPR), R0 to R7, the physical register which the banked registers, R8 to R14, point to depends on the operating mode the 3. Special Purpose Registers. Program counter C. Apart from the above function these registers can also be used to work in. The following figure is a representation of a General Purpose Register and the following table provides a description of each register and the register re A has just one general-purpose register. When a W register is written, as seen in the example above, the top 32 bits of the 64-bit register are zeroed. Registers act as a link between the program and the computer's data storage. Instead operands as well as addresses are stored at the time of program execution. %ax is of 16 bit which combines two 8 bit registers %ah and %al. Jul 25, 2024 · X18 (Platform Register) The X18 platform is a general-purpose register like any. The purpose of an accumulator register is to hold data Jul 23, 2025 · The size of the general-purpose registers affects how much data the CPU can work with at once. They can hold data, memory addresses, or temporary results of arithmetic and logical operations. A General-Purpose Register is defined as a 32-bit register used for data operations in computer systems. If you want to do something with a product, it must first be moved to a general purpose register. These registers are used to store the output of mathematical and logical instructions. Apr 11, 2013 · General purpose registers (GPR) are not used for storing any specific type of information. Sep 19, 2019 · Dive into x86 assembly! Learn about key registers, see simulations of register contents, and gain a detailed understanding of x86 architecture. Register files may be clubbed together as register banks. I/O Space 64 bytes in data memory for CPU peripheral functions (via control registers), SPI, and other I/O functions. Program Counter (PC) The Program Counter (PC) keeps track of the address of the next instruction to be executed. The register file is divided into four banks to provide expanded addressable memory. For IBM System/360, 1964 Class ISA types: Stack, Accumulator, and General-purpose register ISA is mature and stable – Why do we study it? 2 Accumulator General purpose registers were added: r8 … r15. NASM Registers This quick reference is good. They are not tied to a specific function. It is often referred to as the “accumulator” or simply “A” register. Unlike general-purpose registers, which can be used to store and manipulate any type of data as determined by the programmer, SPRs are restricted to particular roles such as holding Sep 20, 2024 · In the 8051 Microcontroller Tutorial, we can see the Instruction Set and Addressing Modes. Oct 20, 2025 · CR8 is a new register accessible in 64-bit mode using the REX prefix. The AAPCS, however, reserves it to be the platform register, pointing to some platform-specific data. In this tutorial, we will take a look at the 8051 Microcontroller Special Function Registers or SFRs. CX is used for looping and counting operations like in We have discussed general purpose registers as being discrete memory locations within the CPU used to hold temporary data and instructions. Move From Hi mflo d # d ← lo. I believe a general-purpose register is a register that can be used for anything (for calculation, for moving of data to/from it, etc. data memory Find the data memory size for the following AVR chips: b) ATmega16 c) ATtiny44 data memory = general purpose register + I/O registers + SRAM b) 32 + 64 + 1024 = 1120 c) 32 + 64 + 256 = 352 Special purpose registers like the Program Counter and Memory Address Register facilitate the fetching of instructions by holding addresses and transferring data between registers. If the platform ABI has no such requirements, then it should use r18 as an additional temporary register. The assembler indicates when it has not detected any references to a register. Registers The 64-bit x86 register set consists of 16 general purpose registers, only 8 of which are available in 16-bit and 32-bit mode. Give the name of this register. Nov 26, 2021 · A CPU register is a small and temporary storage containing a set of data holding places that are part of the computer processor. Figure 3: The Status register. CPU Registers CPU registers are storage built into the CPU itself. 1. Wikipedia has related information at Processor register. Register A serves as an accumulator while Register B functions as a general purpose register. The AH, DH, CH, and BH registers represent the high-order 8 bits of the corresponding registers. Since the The General-Purpose Register Convention table shows how GPRs are used. The figure below shows the register file map inside the The role of register r18 is platform specific. AI generated definition based on: The Definitive Guide to the ARM Cortex-M3 (Second Edition), 2010 Sep 30, 2024 · From general-purpose and special-purpose registers to modern SIMD and vector registers, each type plays a unique role in optimizing CPU performance and supporting the diverse needs of modern computing. Next, use the nonvolatile registers in descending order, starting with GPR31. BX stores memory addresses and data values and is used for memory access. Memory cell ANSWER: D, 2. A register holds an instruction, a storage address, or any kind of data. General Purpose Registers General Purpose Registers. The least significant 8 bits of the first four of these registers are accessible via the AL, BL, CL, and DL in all execution modes. It stores intermediate results during calculations. Data Register ( DR ). There are 4 general purpose registers - AX, BX, CX, and DX. However, there are restrictions. Here we have the picture that we started out with in this discussion and here are the four registers we discussed, the general purpose, instruction, arithmetic, and accumulator. The interrupt mask contains a bit for each of the five interrupt levels. In computer organization, general register organization plays a crucial role in facilitating efficient data storage, retrieval, and manipulation within the (CPU). MOV (to general) Move vector element to general-purpose register. Almost all data manipulation in your program must be done with the general purpose working registers so it is important to understand the instructions they offer and how to use them. Iii. Accumulator Register ( AC ). B. These registers are 128-bit, but like the general-purpose registers, can be accessed in several ways. The general-purpose registers can store any type of data, including integers, floating-point numbers, addresses, and control information. The purpose of an accumulator register is to hold data Aug 2, 2019 · The register asm ("r0") annotations on the declaration of rv require the compiler to put it in r0, and the : "=r" (rv) annotation on the asm statement tells it that the assembly instruction writes to that variable. The instruction buffer is a 6-byte queue of prefetched instructions. In some cases, general purpose register can be used for addressing functions (e. base, GS. Jul 23, 2025 · Accumulator Register Program Counter (PC) Register General-Purpose Registers Instruction Register (IR) Memory Address Register (MAR) Memory Data Register (MDR) Stack Pointer (SP) Floating-Point Registers Fetch When we talk about "fetch'' in computers, it is like a computer going on fetching next instruction which has to be followed. Program Counter Register ( PC ). Find the data memory size for the following AVR chips: (a) ATmega32 (b) ATmega16 (c) ATtiny44 (d) ATmega328 181 What is the difference between the EEPROM and data RAM space in the AVR? 19. AX is used for arithmetic and logical operations and storing results. These are commonly used for thread-pointers in user code and CPU-local pointers in kernel code. A register is a unique high-speed storage area in the CPU. Instruction register B. In the exception handling modes, LR holds the return address for the exception, or a subroutine return address if subroutine calls are executed within an exception. Below is an overview of these instructions. Aug 21, 2025 · General-purpose registers are used to store temporary data within the microprocessor There are 8 general-purpose registers in the 8086 microprocessor. Depending on the settings in the CPACR_EL1, CPTR_EL2, and CPTR_EL3 registers, and the current Security state and Exception level, an The second example uses an explicit base and displacement representation of the destination address, with general–purpose register 8 serving as the explicit base register. Data Register A set of flip-flops forms a register. An accumulator register is a special type of register known for its versatile and fundamental role in computer architecture. The register x0 is hardwired to the constant 0. C and AVR microcontrollers contain 32 8-bit general purpose working registers that are directly connected to the Arithmetic Logic Unit (ALU). These are R0-R12, SP, LR. The difference between RAX, EAX, and AX is their size. The figure below shows the register file map inside the It can also be used as a general-purpose register if the return address is stored on the stack. Mar 1, 2022 · RISC-V defines a set of registers that are part of the core ISA. What is a general-purpose register? A general-purpose register can be used for various tasks, including arithmetic operations and temporary data storage during program execution. Each re ister can hold 8-bit data. For example: when the CPU performs an add operation, the CPU needs the input values for the addition operation. The input values used by the instructions are always stored in a (general purpose) register (= very fast memory cells) that are located inside the CPU After executing an operation, the CPU usually needs to store the result away for safe-keeping: May 8, 2022 · Types of special-purpose registers are Data registers, accumulators, address registers, instruction registers, program counters, temporary registers, input registers, and output registers. A “general-purpose” register (GPR for short) can be used for storing arbitrary integer numbers. , (True/False) The following instruction is invalid: inc [esi] and more. For detailed information, you Figure 9-2. C and C++ compilers use a common procedure-call convention, assigning specific meaning to registers r1 through r23 and r26 through r28. Jul 18, 2020 · General/Multi Purpose Registers As, we have already talked about the fact that general purpose registers can be used for various things. %eax is of 32 bit which combines a 16 bit %ax register and additional 16 Sep 25, 2024 · General Purpose Registers Pointer Registers Segment Registers EFLAGS Register Figure 9-2. This table gives all the basic registers, with special-purpose registers highlighted in yellow. Internal RAM or Data Memory of the 8051 Microcontroller is divided into General Purpose Registers, Bit Addressable Registers, Register Banks and Special Function Registers. He notes that we will Aug 3, 2023 · General-purpose register: The general-purpose register stores data and intermediate results during the execution of a program. However there are also special purpose registers. The registers are configured as follows (From the book) Note that a-d also have *h (ie ah) which is the second lowest 8-bits in the register. Jan 23, 2025 · General-purpose registers are versatile registers that the CPU can use for a variety of purposes. Jan 1, 2024 · The x86 architecture has 8 General-Purpose Registers (GPR), 6 Segment Registers, 1 Flags Register and an Instruction Pointer. A-Level, IB, AP, GCSE, IGCSE, Oxbridge, Ivy league, university admissions. Mar 17, 2025 · In Computer Organisation, the register is utilized to acknowledge, store, move information and directions that are being utilized quickly by the CPU. There is an additional user-visible program counter pc register which holds the address of the current instruction. Explore general-purpose registers in AArch64 architecture, including detailed documentation and technical insights for developers. The description of these general purpose registers Elite online tutoring from the UK's & US's best tutors. g register indirect These are all general purpose. This instruction reads the unsigned integer from the source SIMD&FP register, zero-extends it to form a 32-bit or 64-bit value, and writes the result to the destination general-purpose register. Notice that they all function in respect to the data bus. The computer has instructions that identify which register to use by a number or address, like R0, R1, R7, SP, and PC. Some System/370 systems provide only 24 bits for addressing. , EAX) Each lower-half can be addressed as a 16-bit register (e. They include combinational circuits that implement data processing. Jul 5, 2018 · The general purpose register can contain the operand for any opcode. That's kind of an unusual question when evaluating an individual processor, as the number of registers is generally defined at the architectural level. Output Register. What is a general purpose register? With the exception of ARMv6-M and ARMv7-M based processors, there are 30 (or 32 if Security Extensions are implemented) general-purpose 32-bit registers, that include the banked SP and LR registers. Input Register. Which of the following instructions (as described in the language description table) changes the contents of a memory cell? 21. , AH and AL) The EAX, EDX, ECX, EBX, EBP, EDI, and ESI registers are 32-bit general-purpose registers, used for temporary data storage and memory access. Fifteen general-purpose registers are visible at any one time, depending on the current processor mode. In some cases, 16-bit instructions may only access a subset of these registers, known as low registers (R0–R7). and more. Of the seven remaining general-purpose registers, the data register, EDX, is most closely tied to the accumulator. For example, there may be dedicated register for floating point and stack operations. the type of data stored in it An address as a binary value. The main purpose of a register is to keep a number (variable). General-Purpose Registers (R0, R1, R2…): Jul 19, 2020 · The 8086 die, showing the register storage. Earlier systems relied on the accumulator for temporary data storage during instruction execution. Registers Registers are usually known as data storage devices. 8051 microcontroller has 2 registers, namely Register A and Register B. Ii. GPR1 and GPR2 must be dedicated as stack and Table of Contents (TOC) area pointers, respectively. Figure 3 describes the bits in the Status register that are implemented by SPIM. Two of these A and B hold results of many instructions, particularly arithmetic and logical operations of 8051 CPU. Instructions that deal with over sized data items, such as multiplication, division, CWD, and CDQ, store the most significant bits in the data register and the least significant bits in the accumulator. What is a general purpose register? General purpose registers are used to store temporary data within the microprocessor. The initial data to be processed, the intermediate result, and the final result of the processing operation are all stored in this register. The General Register Organization in computer architecture is a model in which multiple general-purpose registers are available to the CPU instead of just one accumulator. Introduction to Special-Purpose Registers Special-purpose registers (SPRs) are a distinct class of processor registers dedicated to specific functions as defined by the instruction set architecture (ISA). Mar 12, 2001 · Registers in assembly language programmingtable of contents for assembly language section register set accumulators data registers address registers general purpose registers constant registers floating point registers index registers base registers control registers program counter (location counter) processor flags result flags control flags stack pointer subroutine return pointer General-purpose registers CPU registers can be placed into two categories: general-purpose and special-purpose. If we add the I/O registers, internal RAM, and general purpose register sizes together we should get the total space for the 7. Some registers have names recognized by the assembler. When used for addressing, the register is called a base register. In simple terms, an accumulator is a designated register that stores intermediate results and performs arithmetic and logical operations. They are used to store data. g. However, when optimization is on, the compiler may determine that all local variables can be stored in registers. It is used to store the value of the offset. Learn their structure, usage, and role in 64-bit programming. General Purpose Register Following are the sixteen general purpose register : Anatomy of a 64-Bit Register : %ah and %al are 8 bits register. On x64, an operation that writes to a 32-bit register zero-extends the result. General purpose registers in the 8086 microprocessor store temporary data and addresses and are used for arithmetic and logic operations. AVR CPU General Purpose Working Registers Most of the instructions operating on the register file have direct access to all registers, and most of them are single cycle instructions. In this article, we will look into the characteristics, pros, and cons of Aug 7, 2017 · 5 I am trying to understand what criteria a register must have to be called a "general-purpose register". The preferred method of using GPRs is to use the volatile registers first. the register that supplies this data at the end of the Instruction set architecture is the structure of a computer that a machine language programmer (or a compiler) must understand to write a correct (timing independent) program for that machine. Jul 19, 2020 · The 8086 die, showing the register storage. Move From Lo The hi and lo registers cannot be used with any of the other arithmetic or logic instructions. General-Purpose Registers (GPRs) These registers are versatile and can be used for a wide range of tasks, such as arithmetic, logic, and data transfer. The other 32 are in four register banks, RB0 –RB3 of eight registers each. False If we add the I/O registers, internal RAM, and general purpose register sizes together we should get the total space for the _____. Address Register ( MAR ). Overview RISC-V base ISA consists of 31 general-purpose registers x1-x31 which hold integer values. Dec 1, 2020 · The CPU contains 32 general-purpose registers, sometimes they are called general-purpose register files. There are a number of special purpose registers within the CPU. There are 16 general purpose registers in the x86-64 architecture. If a platform ABI has need of a dedicated general purpose register to carry inter-procedural state (for example, the thread context) then it should use this register for that purpose. Feb 1, 2025 · General Purpose Registers (GPRs) are essential components within a CPU, serving as temporary storage locations for data that is actively being processed. The size of the above registers is 16 bit, it's something like: 0011000000111001b (in binary form), or 12345 in decimal (human) form. More on this Apr 22, 2024 · Accumulator Register is a general-purpose Register. But nearly all of them have special purposes too. Here's how Oct 22, 2025 · General Register-Based CPU Organization, uses multiple general-purpose registers instead of a single accumulator. See full list on tutorialspoint. Dec 18, 2024 · The current value of the general-purpose output field of the GPO register is reflected continuously on the GPO I/O signal of the core. 3. Nov 19, 2024 · Types of Registers Registers are categorized based on their functionality into general-purpose registers and special-purpose registers. The eax register in this example is an x86 general-purpose register. It can also be used as a general-purpose register if the return address is stored on the stack. We will start learning how to move small integer values into registers. This provides true general purpose register use. The TLCS-870/C1 has eight registers W, A, B, C, D, E, H and L An accumulator register is a special type of register known for its versatile and fundamental role in computer architecture. When so used, the contents of the register are viewed as an unsigned integer. General-purpose registers can be used for various purposes such as an accumulator and the data handling. Figure 4: The Cause register. , (True/False) The EBX register is usually reserved for addressing the stack. The lower 32/16/8 bits of these registers are referred to as rXd, rXw and rXb. x86-64 has 14 general-purpose registers and several special-purpose registers. Special purpose registers (1) We have discussed general purpose registers as being discrete memory locations within the CPU used to hold temporary data and instructions. Two instructions move the result of a multiplication into a general purpose register: mfhi d # d ← hi. We will be using NASM, and it has the following register reference NASM Registers This quick reference is good. Move that value into one of the (general purpose) register first. This article explores the relationship between accumulators and general-purpose registers, discussing whether an accumulator can be considered a type of general-purpose register and the inclusion of accumulators in general-purpose register architectures. The register used may be either a special register provided for this purpose, or may be any one of the general-purpose registers in the processor. Operand Access: The CPU accesses operands directly Jun 3, 2023 · Totally 34 general purpose registers or working registers. Some of the commonly used registers are: AC ( accumulator ) DR ( Data registers ) AR ( Address registers ) PC ( Program counter ) MDR ( Memory data registers ) IR ( index General-Purpose Registers The general-purpose registers is able to hold 8-, 16-, or 32-bit data. Some GPRs are special nonetheless, as we will see later; but the distinction is “can I store arbitrary integers in it?”. For example, the GPO signal of the core could be used to set an IIC memory device write protect. These general-purpose registers are used to hold dat like any other registers. Types of CPU Registers: General-Purpose and Special-Purpose CPU registers are classified into general-purpose and special-purpose registers based on their roles. Bx is 8 bits, Hx is 16 bits and so on to Qx which is 128 bits. As shown in Figure 1-1, the general-purpose registers are named X0-X31, the value of the first register X0 is always 0, and the registers X1-X31 are readable and writable. The general purpose registers are primarily used like a scratch pad to store values used in computations Because the ALU (Arithmetic and Logic Unit) is the computation circuit of the CPU and the ALU takes inputs from the general purpose registers, a rule of thumb in assembler programming is: Discover the detailed architecture of x64 registers, including general-purpose, segment, and control registers. base MSRs with the addresses 0xC0000100 (for FS) and 0xC0000101 (for GS) contain the base addresses of the FS and GS segment registers. A processor register is a quickly accessible location for a computer's processor. The core eight 16-bit registers are AX, BX, CX, DX, SI, DI, BP, and SP. May 24, 2023 · Instruction Register (IR): The Instruction Register holds the currently fetched instruction being executed. Types and Functions of Computer Registers 1. Home > Electronic Tutorials > Microcontroller Tutorials - PIC > PIC Tutorial 2 - The Registers PIC Microcontroller Tutorial PIC Tutorial 2 - The Registers The Registers A register is a place inside the PIC that can be written to, read from or both. The general purpose registers include the working register and status register, while the special function registers include the program counter, stack pointer and other control registers. If General Purpose Output Width is equal to one, the only bit populated in the register Study with Quizlet and memorize flashcards containing terms like (True/False)PUSHF is used to preserve all general purpose register contents on the stack. The register file is reset on bit stream download (reset value is 0x00000000). These registers are part of coprocessor 0's register set and are accessed by the lwc0, mfc0, mtc0, and swc0 instructions. Interrupt control registers and status register (which contains global interrupt enable bit) are in the I/O space. 3. In either case, it is referred to as an index register. Temporary Register. It is a lot to take in if this is It can also be used as a general-purpose register if the return address is stored on the stack. Then we will learn how to move large (any) integer value into registers. Could you perhaps be more specific as to your question? The general purpose registers perform all the addressing involved in referencing main storage. [1] A processor may have more than one register bank. Special purpose registers hold the Features of a General Register-Based CPU Organization: Registers: In this organization, the CPU contains a set of registers, which are small, high-speed memory locations used to store data being processed. It is of 16 bits and is divided into two 8-bit registers AH and AL to also perform 8-bit instructions. The AX, DX, CX, BX, BP, DI, and SI registers are 16-bit equivalents of the above, they represent the low-order 16 bits of 32-bit registers. Transcendental ( 8-wide ) Double precision unit ( 2-wide ) VALU Vector General Purpose Register ( VGPR ) Core MACC ( 32-wide ) Side MACC ( 32-wide ) Transcendental ( 8-wide ) Despite the name of a register, it's the programmer who determines the usage for each general purpose register. , The Control unit (CU) is a special purpose register. State: I. Memory cell, The Arithmetic/Logic unit (ALU) is circuitry that performs operations on data. The registers spee Aug 2, 2019 · The register asm ("r0") annotations on the declaration of rv require the compiler to put it in r0, and the : "=r" (rv) annotation on the asm statement tells it that the assembly instruction writes to that variable. AVR CPU General Purpose Working Registers Most of the instructions operating on the Register File have direct access to all registers, and most of them are single cycle instructions. Special-Purpose Registers Special-Purpose Registers are used for specific operations related to the functioning of the CPU. As shown in the figure, each register is also assigned a data memory address, mapping them directly into the first 32 locations of the user Data Space. , AX) Each 16-bit register can be addressed as two 8-bit registers (e. The general purpose registers are used to store temporary data in the time of different operations in microprocessor. General Purpose Registers. The general-purpose registers in 8085 processo s are B, C, D, E, H and L. Next we will learn how to move values stored in memory variables into registers and vice versa. This frees up %rbp for use as another general-purpose register. Think of a register as a piece of paper where you can look at and write information on. its function It stores the address of a memory location or an I/O component about to be used (for reading or writing). Study with Quizlet and memorize flashcards containing terms like Which of the following is not contained in a CPU? A. Depending upon the CPU’s micro architecture , the CPU can have different types of registers. AX This is the accumulator. The information is always defined in a register before processing. General purpose registers were added: r8 … r15. Some of the commonly used registers are: AC ( accumulator ) DR ( Data registers ) AR ( Address registers ) PC ( Program counter ) MDR ( Memory data registers ) IR ( index Jan 31, 2025 · What is the Accumulator register (AX)? The accumulator register is a general-purpose register. Accumulator (ACC): The Accumulator is a general-purpose register used for arithmetic and logical operations. Safe to contain anything, since use of a segment does not confer additional privileges to user code. It is of 16 bits and is divided into two 8-bit registers BH and BL to also perform 8-bit instructions. For example, the zero register (r0) always returns the value zero, and writing to zero has no effect. Oct 20, 2025 · FS. , Which of the following is true about the PUSH instruction?, ESP always points to ______ and more. jdyxv eorak pxqpjm akdgs ovil oga dtzzuwk bdnhlh hwdsgy flokptd pjwsl bzbytwp udbxh byux utxrz