The Intel (“eighty-eighty-five”) is an 8-bit microprocessor produced by Intel and introduced in It is a software-binary compatible with the more-famous. Microprocessor: It is a programmable electronics chip (Integrated Circuit ( IC)). A single IC has computing and decision making capabilities similar to. In addition to the microprocessor, a personal computer has a keyboard for The AS/ uses the PowerPC microprocessor with its reduced instruction set.

Author: Faegor Mezizuru
Country: Ethiopia
Language: English (Spanish)
Genre: Photos
Published (Last): 22 January 2012
Pages: 269
PDF File Size: 10.70 Mb
ePub File Size: 15.44 Mb
ISBN: 540-9-92498-258-6
Downloads: 46981
Price: Free* [*Free Regsitration Required]
Uploader: Akinot

Sorensen, Villy January Signals associated with the lower order address bus and time multiplexed higher order address bus comes under this type of signals. All data, control, and address signals are available on dual pin headers, and a large prototyping area is provided.

A single IC has computing and decision making capabilities similar to central processing unit of a computer. microprocessod

Retrieved from ” micdoprocessor Decoder then takes instruction and decodes or interprets the instruction. That kicroprocessor, an operation is performed when the signal goes low. Classification of Signals The various signals in a microprocessor can be classified as Power supply and Frequency signals: Adding the stack pointer to HL is useful for indexing variables in microprkcessor stack frames. It is a large microorocessor heavy desktop box, about a 20″ cube in the Intel corporate blue color which includes a CPU, monitor, and a single 8-inch floppy disk drive.

These are the terminals which are connected to external oscillator to produce the necessary and suitable clock operation. The pins A8-A15 denote the address bus.

Data is provided through the registers. Unlike the it does not multiplex state signals onto the data bus, but the 8-bit data bus is instead multiplexed with the lower 8-bits of the bit address bus to limit the number of pins to Discontinued BCD oriented 4-bit Each of these five interrupts has a separate pin on the processor, a feature which permits simple systems to avoid the cost of a separate interrupt controller.


It has the lowest priority among the interrupts. Output the data from the accumulator to a port with 8bit address.

Pin Diagram and Pin description of Microprocessor

It has the highest nicroprocessor among the interrupts. These are intended to be supplied by external hardware in order to invoke a corresponding interrupt-service routine, but are also often employed as fast system calls.

It is a bit register used to store the memory address location of the next instruction to be executed. A downside compared to similar contemporary designs such as the Z80 is the fact that the buses require demultiplexing; however, address latches in the Intel, and memory chips allow a direct interface, so an along with these chips is almost a complete system.

The Intel ” eighty-eighty-five ” is micrlprocessor 8-bit microprocessor produced by Intel and introduced in Some instructions use HL as a limited bit accumulator. This pin provides the serial output data.

The contents of the accumulator are copied into the memory location specified by the contents of the operand. Each register can hold 8-bit data.

Intel 8085

When an instruction is fetched from memory then it is stored in the Instruction register. Operations that have to be implemented by program code subroutine miroprocessor include comparisons of signed integers as well as multiplication and division. The incorporates the functions of the clock generator and the system controller on chip, increasing the level of integration.

All three microproceessor masked after a normal CPU reset. It is an 8-bit register having five 1-bit flip-flops, which holds either 0 or 1 depending upon the result stored in the accumulator.


A number of undocumented instructions and flags were discovered by two software engineers, Wolfgang Dehnhardt and Villy M. It points to a memory location in read-write memory, called the stack. This block controls the use of the register stack.

To communicate with memory the microprocessor sends an address on the address bus to the memory. Among the interrupts of microprocessor, TRAP is the only non-maskable interrupt.

Microprocessor Data-transfer Instructions

This unit uses the Multibus card cage which was intended just for the development system. This register is used to store 8 bit data and to perform arithmetic and logical operations.

When an instruction of data transfer group is executed, data is transferred from the source to the destination without altering the contents of the source.

ALU includes the accumulator, the temporary register, the arithmetic and logic circuits and flags. Three status signals are available on chip: The 8-bit data is stored in the destination register or memory. Introduction In the previous articles we saw about the architecture of microprocessor. The contents of the register pair designated in the operand are copied onto the stack in the following sequence. Exceptions include timing-critical code and code that is sensitive to the aforementioned difference in the AC flag setting or differences in undocumented CPU behavior.

The DMA controller will inform the system when its current operation has been completed by issuing an interrupt signal.