memory interfacing in 8085 microprocessor pdf

But program memory (EPROM) should be located from address 0000H since reset address of 8085 microprocessor is 0000H.

We can place EPROM/RAM anywhere in full 64 Kbytes address space.

We can have multiple EPROMs and multiple RAMs as per the requirement of application.

It is not always necessary to select 1 EPROM and 1 RAM.

The capacity of program memory and data memory depends on the application.

When both, EPROM and RAM are used, the total address space 64Kbytes is shared by them.

Generally EPROM (or EPROMs) is used as a program memory and RAM (or RAMs) as a data memory.

The total memory size depends upon the application. But it is not always necessary to use full 64Kbytes address space.

Microprocessor 8085 can access 64Kbytes memory since address bus is 16-bit.

4.13 (a) where N is the number of registers and M is the word length, in number of bits.įor Memory Interfacing in 8085, following important points are to be kept in mind. The size of the memory is N x M as shown in Fig. Memory Structure and its Requirements:Īs mentioned earlier, read/write memories consist of an array of registers, in which each register has unique address. In the following section we will see memory structure and its requirements, concepts in Memory Interfacing in 8085 and interfacing examples.

In the last section we have already seen the memory read and memory write machine cycles, and status of the RD, WR and IO/M status signals for read/write operation. The microprocessor activates these signals when it wants to read from and write into memory. This read/write operations are monitored by control signals. The Memory Interfacing in 8085 is used to access memory quite frequently to read instruction codes and data stored in memory. Memory is an integral part of a microprocessor system, and in this section, we will discuss how to interface a memory device with the microprocessor.

Memory interfacing in 8085 microprocessor pdf