Basics. A micro with no non volatile memory (FLASH, in old days would
have been EPROM or ROM) and with no volatile memory (RAM) must be
provided with these external. So a memory map must be created, HW
that differentiates from non-vol and volatile. The 8086 shares its address
pins with both memory areas, so you have to solve how to differentiate
with HW the two areas. Additionally these pins handle data.
See this for description how you differentiate data on this buss -
Microprocessor - 8086 Pin Configuration - 8086 was the first 16-bit microprocessor available in 40-pin DIP (Dual Inline Package) chip. Let us now discuss in detail the pin configuration of a 8086 Microprocessor.
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This processor, and many others, can run code from non-vol (FLASH) or vol
(RAM). In case of volatile when processor starts up it sets its PC Counter
to a address in RAM and starts executing from RAM. But first it has to use
some method of getting program into RAM. Thats done various ways. If
its non vol approach PC and address logic point to FLASH or ROM and code
starts executing from there.
When you write code you must tell the linker what the memory map looks
like, so it know where instructions are located, where variable data is created/
destroyed by memory manager linker links into your code.
It is desired to design a 64kb memory decoder for the 8086 microprocessor using two 16KB SRAM and two 16KB EPROM chips. Assuming the microprocessor wants to write to memory address 0A557H, which chip
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Regards, Dana.
