It is a programmable multipurpose silicon chip, clock driven, register based, accepts binary data as input and provides output after processing it as per the instructions stored in the memory. An accumulator is a register for shortterm, intermediate storage of arithmetic and logic data in a computers cpu central processing unit. The 8085 is called an 8 bit microprocessor because the accumulator is 8 bits in size. General purpose registers in 8086 microprocessor geeksforgeeks. The main differences between microprocessors and microcontrollers are microprocessor has one or two types of bit handling instruction and microcontrollers have much time of bit handling system.
The general purpose registers and the accumulator are accessible to programmer. What is the function of an accumulator in a computer. Why hl pair register in 8085 is called special purpose. Microcomputer a computer with a microprocessor as its cpu. The flag register is a special purpose register and it is completely different from other registers in microprocessor. Al can be used as an 8bit accumulator for 8bit operation. In modern cpus, accumulators have been replaced by general purpose registers because they offer more flexibility. Modern computer systems often have multiple general purpose registers that.
Typically, a hydraulic system with an accumulator can use a smaller pump because the accumulator stores energy from the pump during periods of low demand. In a computers central processing unit cpu, the accumulator is a register in which. Several faster versions of 8085 microprocessor are 8085ah, 8085ah1, and 8085ah2. It is an nmos device having around 6200 transistors contained in a 40 pin dip package. Register are used to quickly accept, store, and transfer data and instructions that are being used immediately by the cpu, there are various types of registers those are used for various purpose. In a computers central processing unit, the accumulator is a register in which intermediate arithmetic and logic results are stored without a register like an accumulator, it would be necessary to write the result of each calculation addition, multiplication, shift, etc. The microprocessor needs to access memory for the purpose of reading instructions. Microprocessor mcqs 1 what does the microprocessor comprise of. Its data bus is 8bit wide and hence, 8 bits of data can be transmitted in parallel from or to the microprocessor. A microprocessor which has n data lines is called an nbit microprocessor i. Today we will study the difference between microprocessor and microcontroller in detail. Microprocessor consists of an alu, register array, and a control unit.
Apart from accumulator 8085 consists of six special types of registers called general purpose. Ax the accumulator bx the base register cx the count register dx the data register. Introduction to microprocessors the microprocessor is one of the most important components of a digital computer. The term accumulator is rarely used in reference to contemporary cpus, having been replaced around the turn of the millennium by the term register. Eu execution unit execution unit gives instructions to biu stating from where to fetch the data and then decode and execute those instructions. It is one of the general purpose register of microprocessor also called as a register.
Lecture note on microprocessor and microcontroller theory vssut. Data and address bus the intel 8085 is an 8bit microprocessor. In a modern computers, any register can function as an accumulator. We have already discussed the general purpose registers, the accumulator, and the flags. In general purpose register machines, a number of registers are available within the cpu. Mar 22, 2017 in this video, we will understand the difference between microprocessor and microcontroller. Alu, timing and control unit, accumulator, general purpose and special purpose registers. In the central processing unit, or cpu, of a computer, the accumulator acts as a special register that stores values and increments of intermediate arithmetic and logic calculations. In a computer s central processing unit cpu, the accumulator is a register in which intermediate arithmetic and logic results are stored. Microprocessor consists of an alu, register array, and. Early 4bit and 8bit microprocessors such as the 4004, 8008 and numerous others, typically had single accumulators. Micro processor 8085 questions and answers by ramesh kumar. The 8085 has six general purpose registers to store 8bit data. Subsequently subtract d from accum gives final result.
Without an accumulator register, it would be necessary to write the intermediate results of each calculation to main memory to read it again for next. A read is counted each time someone views a publication summary such as the title, abstract, and list of authors, clicks on a figure, or views or downloads the fulltext. Jul 15, 2018 in cpu, an accumulator is a register used for storing intermediate results of larger computation. Today the computing power of a powerful microprocessor approaches that a cpu on earlier large computer.
Layout of the intel 80386 generalpurpose microprocessor. Introduction fundamentals of microprocessor 8085 and. The program counter pc this is a register that is used to control the sequencing. In 8bit microprocessors the accumulator is an 8bit register, but some. The pdp11 had 8 general purpose registers, along the lines of the system360 and pdp10. Accumulator based machines use special registers called the accumulators to hold one source operand. What is meant by the statement that 8085 is a 8bit microprocessor. Layout of the intel 80386 general purpose microprocessor. The accumulator is an 8bit register can store 8bit data that is the part of the arithmetic and logical unit alu.
Microprocessor 8086 functional units tutorialspoint. Registers the 80858080aprogramming model includes six registers, one accumulator, and one flag register, as shown in figure. General purpose registers ax accumulator register preferred register to use in arithmetic, logic and data transfer instructions because it generates the shortest machine language code must be used in multiplication and division operations must also be used in io operations bx base register. Kaushik and others published an introduction to microprocessor 8085 find, read and cite all the research you need on researchgate. All data register can be used as either 16 bit or 8 bit. Generalpurpose microprocessors page 2 of figure 2. Visually both microprocessor and microcontroller almost look identical but they are different in many. General purpose registers ax accumulator register preferred register to use in arithmetic, logic and data transfer instructions because it generates the shortest. For instance, a manual calculation of a workers weekly payroll might look.
The microprocessor reads one instruction at a time, matches it with its instruction set, and performs the data manipulation specified. It processes the data as required in the instructions. None of these 3 accumulator based microprocessors examples are. These represent two points in the designspace for instruction sets. Now, you see that there are some special registers, like this accumulator is a. The microprocessor or cpu reads each instruction from the memory, decodes it and executes it. Differences between a microprocessor and a microcontroller. Analog interfacing to embedded microprocessor systems. It is a 16bit specioal purpose register used to hold the memory address of the next intruction which is to be executed. Accumulator acc or a register is extensively used for arithmetic, logical, store and rotate operations. The microprocessor recognizes and processes a group of bits together.
All microprocessors make use of an accumulator register that can supply one. The 80858080a has six generalpurpose registers to store 8bit data. An input device a, an output device b, a rom and a ram are memory mapped to the microprocessor at the addresses as shown in figure. General purpose microprocessors page 2 of figure 2.
In this subject well study about two microprocessors namely intel 8085. This register is used to store 8bit data and to perform arithmetic and logical operations. The result of an operation is stored in the accumulator. The benefit of an accumulator is that it does not need to be explicitly referenced, which conserves data in the operation statement.
Microprocessors 6 microprocessor is a controlling unit of a microcomputer, fabricated on a small chip capable. Microprocessors 6 microprocessor is a controlling unit of a microcomputer, fabricated on a small chip capable of performing alu arithmetic logical unit operations and communicating with the other devices connected to it. As technology has progressed, microprocessors have become faster, smaller and capable of doing more work per clock cycle. Microprocessor architecture and its operations lecture 2. Microprocessormicrocontroller the first microprocessor to make it into a home computer was the intel 8080, a complete 8bit computer on one chip. The special purpose registers used in 8085 microprocessor are. Devices a and b have four addressable registers each ram has 8. The difference between accumulatorbased and register. He can store data in these registers during writing his program.
It is generally used for temporary storage of data and for the placement of final result of arithmeticlogical operations. Out of the two operands to be operated upon, one comes from accumulator acc, whilst the other one may be. The result of the operation is stored in the accumulator. A binary digit is called a bit which comes from b inary dig it. It has 8bit accumulator, flag register, instruction, register, six 8bit general purpose. Difference between microprocessor and microcontroller youtube. Registers the 8085 microprocessor includes six registers, one accumulator, and one flag register, as shown in fig 1.
A microprocessor is an integrated circuit designed to function as the cpu of a microcomputer. The microprocessor is a multipurpose, clock driven, register based, digital integrated circuit that accepts binary data as input, processes it according to. Registers b, c, d, e, h and c and five 16bit registers sp. Interview questions on microprocessor with detailed answers. The number of bits in a microprocessor s word, is a measure of its. Apart from accumulator 8085 consists of six special types of registers called general purpose registers. Read here to learn about the working of hydraulic accumulators, the basic components of a hydraulic accumulator, and factors which limit the pressure inside the accumulator. After processing the necessary operations, the result is stored back in accumulator. It is upward compatible with microprocessor 8080, which is the earlier product of intel.
For example, if we need to compute the expression a. We already know that every computer has its own processor. Difference between microprocessor and microcontroller with pdf. What is the technology used in the manufacture of 8085. Without an accumulator register, it would be necessary to write the intermediate results of each calculation to main memory to read it again for next operation. Microcontroller microprocessor with built in memory and ports and can be programmed for any generic control application.
Basic concepts of microprocessors differences between. After performing arithmetical or logical operations, the result is stored in accumulator. Parker hannifin corporation, climate and industrial controls group, cleveland, oh page 4 catalog c1, accumulators and receivers utube style accumulators the utube accumulator design is a result of extensive laboratory testing plus detailed investigation of the various accumulators currently available. F is a function of n binary variables, the kth variable being the ith bit in the data x. Difference between microprocessor and microcontroller. A microprocessor is an integrated circuit ic which incorporates core functions of a computers central processing unit cpu. The 8051 microcontroller has two, a primary accumulator and a secondary. General purpose registers are used to store temporary data within the microprocessor. Uses data from memory and from accumulator to perform arithmetic. What is the difference between an accumulator instruction set architecture and a general purpose register instruction set architecture. Among of the some mostly used registers named as ac or accumulator, data register or dr, the ar or address register, program counter pc, memory data register mdr,index register,memory buffer. The accumulator is the special register of the computer. In the accumulator based, operations are done via interaction with the accumulator register at each step of the way. Deshmukh, skncoe, comp ax the accumulator bx the base register cx the count register dx the data register.
Register organization general data register the registers ax, bx, cx and dx are the general purpose 16bit registers. Lecture note on microprocessor and microcontroller theory and. The 80858080aprogramming model includes six registers, one accumulator. The registers ax, bx, cx and dx are the general purpose 16bit registers. Have you ever wondered how pressure energy is stored in hydraulic accumulators. There are 8 general purpose registers in 8086 microprocessor. At the bottom of the articles you can download pdf. The accumulator is a temporary memory location that is accessed speedily by the cpu.
However, accumulators may still be found in some special purpose processors. Arithmetic and logic unit as the name suggests, it performs arithmetic and logical operations like addition, subtraction, and, or, etc. Accumulator is an 8 bit register which stores data and performs arithmetic and logical operations. Without a register like an accumulator, it would be necessary to write the result of each calculation addition, multiplication, shift, etc.
The lower 8bit is designated as al and higher 8bit is designated as ah. Alu gets its input from accumulator and temporary register. A microprocessor has five address lines a 4 a 0 and eight data lines d 7 d 0. Microcontroller microprocessor with builtin memory and ports and can be programmed for any generic control application. Tutorial on introduction to 8085 architecture and programming. A microprocessor is a multipurpose programmable device that performs the. The accumulator is an 8bit register that is a part of arithmeticlogic unit alu. In cpu, an accumulator is a register used for storing intermediate results of larger computation.
It consists of 8 bits and only 5 of them are useful. Accumulators usually are installed in hydraulic systems to store energy and to smooth out pulsations. Generalpurpose microprocessor used in general computer system and can be used by programmer. Previous gate questions on microprocessors and memory. General purpose registers normally used for storing temporary results each of the registers is 16 bits wide ax, bx, cx, dx can be accessed as either 16 or 8 bits ax, ah, al prof. Lecture note on microprocessor and microcontroller theory.
A microprocessor is a computer processor that incorporates the functions of a central processing unit on a single integrated circuit ic, or sometimes up to 8 integrated circuits. The processing is in the form of arithmetic and logical operations. What is the difference between accumulator based cpu and. What is the purpose of adc instruction according to 8085. A microprocessor executes instructions given by the user instructions should be in a language known to the microprocessor. It is of 16 bits and is divided into two 8bit registers ah and al to also perform 8bit instructions. General purpose microprocessor used in general computer system and can be used by programmer for any application. Illustrations provided include the kinetic energy recovery system or kers system of race cars, cutaway drawings of some different styles of. Microprocessor architecture the microprocessor can be programmed to perform functions on given data by writing specific instructions into its memory. The accumulator is the register associated with the alu operations and sometimes io operations. Accumulator register an overview sciencedirect topics. It is of 16 bits and is divided into two 8bit registers ah and al. Ax is used as 16bit accumulator, with the lower 8bits of ax designated as al and higher 8bits as ah.
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