4 - Chapter 4 Memory and Storage 1 Introduction In computer...

Info iconThis preview shows pages 1–12. Sign up to view the full content.

View Full Document Right Arrow Icon
1 Chapter 4 Memory and Storage
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
2 Introduction In computer terminology, memory usually refers to RAM, ROM and storage refers to hard disk, floppy disk and CD ROM. Microprocessor-based systems rely on storage devices and memories for their operation to store programs and retain data during processing.
Background image of page 2
3 Basics of Semiconductor Memory Units of binary data: Bit, Nibble (4 bits), Byte (8 bits) A single binary bit is stored in a memory cell An organized group of cells is called an array
Background image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
4 Basics of Semiconductor Memory Memory cells are organized by columns and rows A single unit of data occupies one row and a number of columns of cells 8 columns for a byte of data 16 columns for a word of data 32 columns for 32-bit data (4 Bytes)
Background image of page 4
5 Basics of Semiconductor Memory The location of a unit of data is called the address The number of units that can be stored in a memory is the memory’s capacity
Background image of page 5

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
6 Basics of Semiconductor Memory Data can be put into memory and read from the memory. The write operation puts data into a specified address in the memory, read operation copies data out of a specified address in the memory. Data bus is used to transfer the data bidirectionally. Address bus is used to select carry the desired address.
Background image of page 6
7 Basics of Semiconductor Memory Write Operation To store a byte of data in the memory, a code held in the address register is placed on the address bus. Once the address code is on the bus, address decoder decodes the address and selects the specified location in the memory. The memory then gets a write command, and the data held in the data register is placed on the data bus and stored in the selected memory address, thus completing the write operation. When a new data byte is written into a memory address, the current data byte stored at that address is overwritten.
Background image of page 7

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
8 Basics of Semiconductor Memory Write to memory Write to memory
Background image of page 8
9 Basics of Semiconductor Memory Read Operation A code held in the address register is placed on the address bus. Once the address code is on the bus, the address decoder decodes the address and selects the specified location in the memory. The memory then gets a read command, and a “copy” of the data byte that is stored in the selected memory address is place on the data bus and loaded into the data register, thus completing the read operation. When a data byte is read from the memory address, it also remains stored at that address.
Background image of page 9

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
10 Basics of Semiconductor Memory Read from memory Read from memory
Background image of page 10
11 Random-Access Memories (RAMs) RAMs are read/write memories in which data can be written or read from any selected address in any sequence. A RAM is typically used for short-term data storage
Background image of page 11

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Image of page 12
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 10/23/2011 for the course BME KUEU taught by Professor Ting during the Fall '10 term at Universiti Teknologi Malaysia.

Page1 / 47

4 - Chapter 4 Memory and Storage 1 Introduction In computer...

This preview shows document pages 1 - 12. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online