The x86 Microprocessors: 8086 to Pentium, Multicores, Atom and the 8051 Microcontroller, 2nd Edition

7

Memory and I/O Decoding

IN THIS CHAPTER, YOU WILL LEARN

• The pin functions of a typical memory chip.
• The technique of memory address decoding.
• The reason and logic of using partial address decoding.
• The reason for organizing memory in banks.
• The principles of I/O address decoding.

Introduction

In the previous chapter, we discussed the hardware structure of 8086 and a few ICs which have to be used along with it. Now, we will delve a bit deeper – the focus of this chapter will be on the way memory and I/O are connected to the processor.

Let us start with memory. Whenever we talked about reading or writing from memory, an address was referred to. Assuming that memory is byte organized, it is thought that every location in memory which can ...