Comparison between 8086 and 8088, Assembly Language

Comparison between 8086 and 8088

All the changes in 8088 above 8086 are indirectly or directly related to the 8-bit, 8085 compatible data and control bus interface.

1) The predecoded code queue length is reduced to 4 bytes in 8088, whereas the 8086 queue have 6 bytes. This was done to get ride from the unnecessary prefetch operations and optimize the use of the bus by BIU when prefetching the instructions.

2) The 8088 bus interface unit will fetch a byte from memory to load the queue each time, if at least one byte is free. In case of 8086, at least two bytes should be free for the next fetch operation.

3) The whole execution time of the instructions in 8088 is affected by the 8-bit external data bus. Now all the16-bit operations require additional 4 clock cycles. The CPU speed is also restricted by the speed of instruction fetches.

 

The pin assignments  of both the CPUs are closely identical, however, they have the following functional changes.

1.) A8-A15 already latched, every time valid address bus.

2. ) BHE has no meaning as the data bus is only of 8-bits.

3.) SS0 provides the S0 status information in  theminimum mode.

4.) IO/M has been inverted to be compatible with 8085 bus structure

 

Posted Date: 10/10/2012 4:04:01 AM | Location : United States







Related Discussions:- Comparison between 8086 and 8088, Assignment Help, Ask Question on Comparison between 8086 and 8088, Get Answer, Expert's Help, Comparison between 8086 and 8088 Discussions

Write discussion on Comparison between 8086 and 8088
Your posts are moderated
Related Questions
Interrupt Priority Management The interrupt priority management logic indicated in given figure can be implemented in several ways. It does not required to be present in system

Write an assembly language program that will: accept keyboard input of a positive integer value N; compute the sum S= 1+ 2 + 3 + ... + N; print (output) the computed su

Using DEBUG DEBUG.COM is a DOS efficacy that facilitates the trouble-shooting and debugging of assembly language programs. In particular case of personal computers, all of th

Pin diagram of 8088 : The pin diagram of 8088 is shown in given figure. Most of the 8088 pins and their functions are exactly similar to the corresponding pins of 8086.  Hence

Instruction Formats A machine language instruction format has 1 or more number of fields linked with it. The first field is known as operation code field or op code field, whic

Queue Operation :   RQ/CT0, RQ/G1-Request/Grant:   These pins are utilized by other local bus masters, in themaximum mode, to force the processor to release the loca

1. Start your program at address $8500. To do this you need to inform the assembler, through the EQU and ORG assembler directives, that you want your program to start at $8500. Thi

) What is the difference between re-locatable program and re-locatable data?

Intel's 8237 DMA controller : 1) The 8237 contain 4 independent I/O channels 2) It contains 27 registers, 7 of which are system-wide registers and 5 for each channel. 3)

Explain the basic method for implementing paging