Memory Organization Computer Organization and Architecture by Ravinder Nath Rajotiya - January 4, 20230 Memory Organization Every computer system has following types of memory devices. The different types of memory can be explained as the memory hierarchy. Memory Hierarchy: The total capacity of the memory in a system can be visualized as a hierarchy of memory devices. It includes all memory devices employed in a computer from large size but very slow-speed to small size but very-high speed devices. The memory hierarchy can be represented as shown in figure below. IOP is used to communication between main memory and the auxiliary memory. Cache is used to communicate between CPU and the main memory. Internal or the primary memory: The internal memory consists of random access memory (RAM), read only memory (ROM) and some high-speed memory such as cache memory.
Program to Read from external memory 8051 Expriments by Ravinder Nath Rajotiya - June 3, 2021May 9, 20220 Objectives: To learn interfacing of external memory with 8051 To understand the instructions for accessing the memory To develop a program to read and write data to external memory Theory: 8051 Microcontroller on the other hand has onchip 4KB of ROM and 128B of RAM. 8052 has 8KB of program memory (ROM) and 256 bytes of data memory (RAM). For simple to less complex applications this is sufficent, but, If the program and data tend to be larger and require more memory than available on 8051/8052 then external RAM and ROM can be interfaced with 8051 microcontroller. Thus, there is a provision of connecting both external RAM and ROM i.e., Data Memory and Program. Interfacing memory with 8051 We can interface a maximum of