Intel 8086 and 8088

• If 8 or 16 bit data is required for executing the instruction present in register/register pair and named of register/register pair is given along the register.this instruction is called register addressing mode instruction.
• for example:
• MOV B,A

Linear data structure is used to convert the logical address to physical address .Stack is used in this and the various conversion such as postfix,prefix and infix notation are come in this

You can address 214 or 16384 different locations with 14 address lines.

- An MMU (memory management unit) generates physical address.

- A CPU (central processing unit) generates a logical address.

In Computerprocessors, the overflow flag (sometimes called Vflag) is usually a single Bitin a system Status_registerused to indicate when an Arithmetic_overflowhas occurred in an operation.

Look for the bit of paper in the box marked 'instructions'.

Address binding of instructions and data to memory addresses can happen at three different stages:

Compile time: If memory location known a priori, absolute code can be generated; must recompile code if starting location changes.

Load time: Must generate relocateable code if memory location is not known at compile time.

Execution time: Binding delayed until run time if the process can be moved during its execution from one memory segment to another. Need hardware support for address maps (e.g., base and limit registers).

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The various addressing modes that are defined in a given instruction set architecture define how machine language instructions in that architecture identify the operand (or operands) of each instruction. An addressing mode specifies how to calculate the effective memory address of an operand by using information held in registers and/or constants contained within a machine instruction or elsewhere.

A segment register is a register that contains the base address, or something related to the base address, of a region of memory. In the 8086/8088, the four segment registers are multiplied by 16 and added to the effective address to form the physical address.

An index register, on the other hand, is a register that contains an address that is added to another address to form the effective address.

In the 8086/8088, four address components are involved; 1.) the displacement contained within the instruction, often called the offset, 2.) a base address specified by the r/m field, often the BP or BX register, 3.) an index address specified by the r/m field, often the SI or DI register, and 4.) the segment address specified by context or by a segment override prefix, often the CS, DS, SS, or ES register.

The stack is a region of memory set aside to store register values and operands.

To find out the time interval between two consecutive events using the 8086, or any other processor or programming language for that matter, you observe some time reference when you see the two events, and you subtract the time references from each other to calculate elapsed time.

Unfortunately, the 8086 does not have an interval timer, so you either have to program one using some kind of periodic clock, or you have to measure time using a hard coded loop.

Method One: Interrupts for both

The periodic clock, for instance running at 1 kHz, generates a 1 mS interrupt. In the interrupt service routine, you increment a variable that represents time in mS. The monitored event also generates an interrupt. On the first interrupt, you note the interval time so far. On the second interrupt, you note and compute the time difference. In this example, you have a resolution of 1 mS.

If you were to use an original IBM PC, you would have a clock interrupt available with a frequency of 55 Hz, giving you a resolution of about 18.2 mS.

Method Two: Interrupts for one

The periodic clock runs as an interrupt, as described before. In a loop, you monitor the event, noting the interval time between susequent events, and calculate the time difference. The loop consumes all CPU time while running, which might be a problem.

Method Three: External clock

You have an external counter, perhaps running at 1 mHz. Either hard coded or in an interrupt service routine, you monitor the event, read the clock twice, and calculate the time. In this example, you have a resolution of 1 uS.

Method Four: Brute force

You have a loop that counts iterations in some variable, noting how many iterations there are between events.

While this method requires the least amount of hardware, it is the poorest method, both from the standpoint of overall system threading, and from the standpoint of accuracy.

The loop consumes all processing time. You cannot do anything else during that time, otherwise the results will be wrong. If you are designing a system with multiple processes and threads, this will not work.

The loop also does not have an easily predictable period. Memory latency, cache hit/miss ratio, and other ongoing interrupts will disturb the results. In a single threaded system, and that includes whatever operating system you use, it can work, and it can have repeatable results - and you will need to spend some time calibrating it.

A memory with a 16 bit address bus can address 216 or 65536 distinct items. If each item is 32 bits in size, then the item is 4 bytes. The size of this memory is then 262144 bytes. (256Kb)

The INT 21H instruction in the 8086 is a software interrupt to vector 21H. In order for it to be used for input/output, the programming that responds to INT 21H must be present. This is part of the Operating System.

8086 has four multipurpose registers. 1. AX (Accumulator Register) 2. BX (Base Register) 3. CX (Count Register) 4. DX (Data Register) By Aneeta Arshad

Yes, and in that case it is a point.

explain address decoding technique

When a processor is interrupted to do a particular task,Program counter should be loaded with the the address of subroutine(task).If the processor automatically generates the address then it is known as vectored interrupt.for example if 8085 microprocessor is interrupted through RST 5.5 pin,then processor multiplies 5.5 by 8 and converts it to Hex address.If user has to provide address of subroutine using CALL instruction then it is known as non vectored interrupt

Language processor consist of two phases

1.Analysis phase

2.Synthesis phase

Language processor pass is the processing of every statement in a source program, or its equivalent representation to preform language processing function

pass 1-It analyses the source program and notes relevant information.

pass 2- It synthesizes the target program

Personal information on notable individuals is not made public because of privacy and security concerns.

00 to 0F represents 16 addresses Binary representation is 1111 therefore you need 4 address lines to connect to all addresses

Visual Display Unit 's Base Memory Address. - Every device in a computer requires a unique base memory address ( an address that the computer systems Bi/oS uses to locate a device) As each device has a unique area of memory, the computer knows that when it uses this area it will be for that device, and thus be able to communicate with the device. Extended Bi/oS can be found on expansion cards with new functions or updated functions. This must be treated as a device so that the currecnt system Bi/oS can read the extended Bi/oS contained on the card, and use them.

usually this means your motherboard doesn't recognize your model of CPU. it will run fine, it just doesn't know exactly what kind of CPU you have. try updating your bios.