can anybody please tell me why there are no single RD/WR pin in microprocessor even though microprocessor anyone of the function at a time?

 

It is not a microcontroller. It is a full 16 bit CPU. It is a bit dated (old), the old XT computers were based off this CPU.

The 8086 and the 8088 are very closely related.

Being a CPU you are expected to provide RAM/ROM and all I/Os. It did not require a heat sink, unlike the next generation 80286's (and they did not require a fan).

 

What's actually he is trying to ask?

 

My assumption is the OP is trying to treat this venerable old chip like a modern µC, which has memory (both flash and RAM) as well as the program pins. It may be much older than he/she is.

You need to ask the questions, to clear the way for new questions. I've worked on optical test equipment in the 90's that used this old chip, it was kinda fun.

 

May be he is talking about the Motorola family of CPU which uses RD/WR signal (using only one signal wire) for external I/O and memories..Low to write while High to read.

Whereas the Intel family of MPU and MCU used 2 signal wires /RD and /WR to do read and write for their I/O and memories. Even the 8051 mcu has separate read and write wires for external memories.

Allen

 

And does this apply to a 8086, which was specifically mentioned? He also used the term microcontroller, which is something specific, and definitely does not cover a CPU chip of any generation.

At this point we are going to have to wait from the OP to see what he wants.