Microprocessors darshan institute of engineering and technology. So the data bus present in the microprocessor is also 8bits wide. Draw the architecture of 8085 and mention its various functional blocks. The control bus is bidirectional and assists the cpu in synchronizing control. Flag register of 8085 microprocessor with example 8085. So 8bits of data can be transmitted from or to the microprocessor. We have already discussed the general purpose registers, the. The memory interfacing in 8085 is used to access memory quite frequently to. Bus also carries instructions from memory to the microprocessor. Let us discuss the architecture of 8085 microprocessor in. Each microprocessor is designed to execute a specific group of operations. Pdf intel 8085 microprocessor architecture anurudh kashya. This is a multipurpose instruction and used to implement the 8085 interrupts 7.
All the address, data and control lines are available at the edge connector. This was introduced by the intel company in the year 1977 to 1990. An instruction is a command to the microprocessor to perform a given task on a specified data. Bus structure of 8085 microprocessor 8085 microprocessor. A free powerpoint ppt presentation displayed as a flash slide show on id. Internal architecture of 8085 microprocessor learn about. It is a group of wires or lines that are used to transfer the addresses of memory or io devices. System bus a bus is a path through which data is transferred from one component to other inside system.
Memory interfacing in 8085 memory structure wait state. The time for the back cycle of the intel 8085 a2 is 200 ns. The memory interfacing in 8085 is used to access memory quite frequently to read instruction codes and data stored in memory. The processing of bits in the p is also in parallel. Tutorial on introduction to 8085 architecture and programming. Bus structure of 8085 microprocessor the microprocessor mpu performs various operations with peripheral devices or a memory location by using three sets of communication lines called buses. A bus has a wire or line for each bit and thus allows exchange of all bits of a word in parallel. What is the function of an address bus and a data bus in a. Questions on introduction to microprocessor 8085 instruction. The entire group of instructions that a microprocessor supports is called instruction set. It is a 8 bit microprocessor, introduce by intel in 1976. The address bus carries the address of memory location to be written or to be read from. The evolution of microprocessors was divided into five generations such as first, second, third, fourth and fifth generation and the characteristics of these generations are discussed below.
It includes the alu, register arrays and control circuit on a single chip. We use your linkedin profile and activity data to personalize ads and to show you more relevant ads. Before knowing about the 8085 architecture in detail, lets us briefly discuss about the basic features of 8085 processor. The microprocessor unit performs primarily four operations. The 8080 processor was updated with enabledisable instruction pins and interrupt pins to form the 8085 microprocessor. Microprocessor uses control bus to process data that is what to do with the selected memory location. In this article you will get to know about the definition, architecture, block diagram and working of. Mvi b, 3eh move the data 3eh given in the instruction to b register. The address and data bus are multiplexed in this processor which helps in providing more control signals. Cpu internal structure the internal architecture of the 8085 cpu is capable of performing the following operations.
This means that microprocessor 8085 can transfer maximum 16 bit address which means it can address 65,536 different memory locations. Lecture note on microprocessor and microcontroller theory and. Interruptstructure of 8085 free 8085 microprocessor lecture. The compiler is used to translate a high level language to assembly level language because the length of code is relatively short and an extra ram is used to store the. The functional components of a cpu are arithmetic logic unit alu, control and timing units, registers are found in a single integrated circuit called ic. The 8085 uses a total of 246 bit patterns to form its instruction set. Diagram to represent bus organization system of 8085 microprocessor. These lines are used for data flowing in both direction means data can be transferred or can be received through these lines. The instruction interprets the accumulator contents as follows. Lecture note on microprocessor and microcontroller theory vssut. Microprocessor goes to 003c location and will get a jmp instruction to the actual isr address. In intel 8085 microprocessor, address bus was of 16 bits. It is an 8 bit general purpose microprocessor that can easily store 64k bite of memory. The microprocessor has become more essential part of many gadgets.
It is a softwarebinary compatible with the morefamous intel 8080 with only two minor instructions added to support its added interrupt and serial inputoutput features. As discussed earlier, 8085 microprocessor was introduced by intel in the year 1976. Questions on introduction to microprocessor 8085 instruction set mcq type questions 1. The execution steps are repeated for all the instructions of the system bus used in 8085 program until the last instruction. The width of a bus is the number of signal lines that constitute the bus. Bus is a group of conducting wires which carries information, all the peripherals are connected to microprocessor through bus. Microprocessor 8085 can address location upto competitive. The bus over which the cpu sends out the address of the memory location is known as address bus.
It was compatible with intel 8080 but needed less support of the hardware. The kit is fully expandable for any kind of application. Complex instruction set microprocessor the processors are designed to minimise the number of instructions per program and ignore the number of cycles per instructions. The intel 8085 eightyeightyfive is an 8bit microprocessor produced by intel and introduced in march 1976. Various operations are performed by microprocessor with the help of control bus. According to computer architecture, a bus is defined as a system that transfers data between hardware components of a computer or between two separate computers. Microprocessor 8085 notes free download as word doc. Each instruction is represented by an 8bit binary value. Instruction set of 8085 an instruction is a binary pattern designed inside a microprocessor to perform a specific function. Evolution of microprocessor types and applications. Circuits digital electronics an introduction to microprocessor. The first 8 lines address bus and 8lines data bus are multiplexed ad0ad7.
It is a 40 pin c package fabricated on a single lsi chip. But 8085 processor requires 16 bit address bus as the memory addresses are 16bit wide. The 8085 uses a total of 246 bit patterns to form its. Ppt the 8085 microprocessor architecture powerpoint. Its data bus width is 8bit and address bus width is 16bit, thus it can address 216 64 kb of memory. Lecture note on microprocessor and microcontroller theory. Central processing unit cpu is carved on a single chip is called a microprocessor. Video lectures on microprocessors and microcontrollers by prof. The reason for the difference is that some actually most instructions have multiple different formats. System bus connects cpu and memory and other components inside system. Memory is an integral part of a microprocessor system, and in this section, we will discuss how to interface a memory device with the microprocessor. To find the smallest number in an array of data using 8085 instruction set. Jun 05, 2015 we use your linkedin profile and activity data to personalize ads and to show you more relevant ads. Intel 8085 8bit microprocessor intel 8085 is an 8bit, nmos microprocessor.
In this article you will get to know about the definition, architecture, block diagram and working of 8085 microprocessor. The maximum addressable memory space is a 64k b 16 k c 8k d 4k 2. The 8085 machine language the 8085 from intel is an 8bit microprocessor. Bus organization of 8085 microprocessor geeksforgeeks. The 8085 microprocessor architecture 8085 instruction set data transfer operations between registers between memory location and a register direct write to a. What is address bus, data bus and control bus in microprocessor. So it can be used to carry the 8 bit data starting from 00000000h00h to 11111111hffh. The microprocessor uses the address bus to per form the first function mentioned in step. This microprocessor is an update of 8080 microprocessor.
Some control signals are read, write and opcode fetch etc. Microprocessor 8085 communicates via its address bus of 2bytes width. The schematic representation of the 8085 bus structure is as shown in fig. Mainly in the microprocessor based system the interrupts are used for data transfer between the peripheral and the microprocessor. Cpu central processing unit alu arithmeticlogic unit control logic registers, etc memory input output interfaces processor system architecture interconnections between these units. The 5 in the model was added as it requires plus 5 voltages. Microprocessor with a 16 bit address bus is used in a linear memory selection configuration address bus lines are directly used as chip selects of memory chips with four memory chips.