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.

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Lastly, the carry flag is set if a carry-over from bit 7 of the accumulator the MSB occurred.

8085 Data-transfer Instructions

Device wishing to perform DMA asserts the processors bus request mmicroprocessor. The ALU includes five flip-flops. This is provided by CLK pin. This was typically longer than the product life of desktop computers. Many of these support chips were also used with other processors.

Microprocessor Pin Diagram Explained

Each instruction has two parts, one is task to be performed, called the operation code opcodeand the second is the data to be operated on called the operand. It points to a memory location in read-write memory, called the stack.

Load H and L registers direct.

It has the lowest priority among the interrupts. This block controls the use of the register stack.

The device then asserts the bus grant ack signal. Week 8 Aug 27 30 upvotes. These are nothing but the restart interrupts. The has extensions to support new interrupts, with three maskable vectored interrupts RST 7. The number of bits that can be stored in a register or memory element is called a memory word.


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. In simple words clock cycle refers to the transition between o volts to 5 volts and back to 0 volts. It has a bubble memory option and various programming modules, including EPROM, and Intel and programming modules which are plugged into the side, replacing stand-alone device programmers.

Pin Diagram and Pin description of 8085 Microprocessor

In the previous article we saw how ALE helps in demultiplexing the lower order address and data bus. From Wikipedia, the free encyclopedia.

Decoder microprocsesor takes instruction and decodes or interprets the instruction. All interrupts are enabled by the EI instruction and disabled by the DI instruction.

All the above mentioned interrupts are maskable interrupts. The can also be clocked by an external oscillator making it feasible to use the in synchronous multi-processor systems using a system-wide common clock for all CPUs, or to synchronize the CPU to an external time reference such as that from a video source or a high-precision time reference.


A bit binary number is called a word in a bit processor. More complex operations and other arithmetic operations must be implemented in software.

A number of undocumented instructions and flags were discovered by two software engineers, Wolfgang Dehnhardt and Villy M. Accepts data from input device.

Comments Write a comment. The contents of the designated register pair point to a memory location. Copy H and L registers to the stack pointer. The original development system had an processor. This page was last edited on 16 Novemberat Subtraction and bitwise logical operations on 16 bits is done in 8-bit steps. The instruction loads bit data in the register pair designated in the register or the memory.

A 1-byte instruction includes the opcode and operand in the same byte. Discontinued BCD oriented 4-bit SIM and RIM also allow the global interrupt mask state and the three independent RST interrupt mask states to be read, the pending-interrupt states of those same three interrupts to be read, the RST 7. Intel An Intel AH processor.

Microprocessor communicates with memory and other devices input and output using three buses: That is, they can be enabled or disabled using programs.