digital fundamentals 10th edition powerpoint

DIGITAL FUNDAMENTALS 10TH EDITION POWERPOINT 32 BIT
DIGITAL FUNDAMENTALS 10TH EDITION POWERPOINT 64 BITS
DIGITAL FUNDAMENTALS 10TH EDITION POWERPOINT CODE

DRAMs are simple and cost effective, but require refresh circuitry to prevent losing data.

Read cycle sequence: A valid address is put on the address bus Chip select is LOW Output enable is LOW Data is placed on the data bus Memory array Address lines Row decoder 256 rows x 128 columns x 8 bits Eight input buffers Write cycle sequence: A valid address is put on the address bus Chip select is LOW Write enable is LOW Data is placed on the data bus Output data I/O0 Input data control Column I/O Column decoder I/O7 Address lines CS WE OE See text Figure for the waveforms…ĭynamic RAMs (DRAMs) store data bits as a charge on a capacitor. The basic organization of an asynchronous SRAM is shown. SRAMs are available in many configurations – a typical large SRAM is organized as 512 k X 8 bits. SRAM is faster than DRAM but is more complex, takes up more space, and is more expensive. The cells are organized into an array of rows and columns. Bits stored in a semiconductor latch or flip-flop Bits stored as charge on a capacitorġ0 Summary Static RAM SRAM uses semiconductor latch memory cells. Two categories are static RAM (SRAM) and dynamic RAM (DRAM). It is read/write memory and can store data only when power is applied, hence it is volatile. A copy of the data is placed in the data bus and shifted into the data register. Address register Data register Address decoder Byte organized memory array Address bus The address is placed on the address bus. The data bus is a “two-way” path data moves from the memory during a read operation. The read operation is actually a “copy” operation, as the original data is not changed.

A simplified write operation is shown in which new data overwrites the original data. The two main memory operations are called read and write. Output Enable (OE) is active during a read operation, otherwise it is inactive. All other inputs are ignored if the Chip Select is not active. Chip Select (CS) or Chip Enable (CE) is used as part of address decoding. Read Enable (RE) and Write Enable (WE) signals are sent from the CPU to memory to control data transfer to or from memory. Depending on the type of memory, other signals may be required. In addition to the address bus and data bus, semiconductor memories have read and write control signals and chip select signals.

DIGITAL FUNDAMENTALS 10TH EDITION POWERPOINT 32 BIT

A 32 bit address bus can access 232 locations, which is approximately 4G. Its size determines the number of locations that can be accessed. The address bus is a group of conductors with a common function. Data is then moved to or from the data bus. Internal decoders decode the address to determine the specific location.

DIGITAL FUNDAMENTALS 10TH EDITION POWERPOINT CODE

In order to read or write to a specific memory location, a binary code is placed on the address bus. Typical computer memories have 256 MB or more of capacity. Question How many bytes are shown? What is the location of the blue byte? Answers a) 64 B b) Row 2, column 8 This example is (of course) only for illustration. Each byte has a unique row and column address. For example the blue byte is located in row 7.Ĥ Summary Question Answers Memory AddressingĪ 3-dimensional array is arranged as rows and columns. In a 2-dimensional array, a byte is accessed by supplying a row number. In PCs, a byte is the smallest unit of data that can be accessed.

DIGITAL FUNDAMENTALS 10TH EDITION POWERPOINT 64 BITS

In assembly language, a 32 bit entity is called a double-word and 64 bits is defined as a quad-word.ģ Summary Memory Units The location of a unit of data in a memory is called the address. For historical reasons, assembly language defines a word as exactly two bytes. By this definition, a word is equal to the internal register size (usually 16, 32, or 64 bits). Generally, a word is defined as the number of bits handled as one entity by a computer. Computer memories are organized into multiples of bytes called words. The most common unit is the byte, which by definition is 8 bits. 1 Digital Fundamentals Tenth Edition Floyd Chapter 10Ģ Summary Memory Units Memories store data in units from one to eight bits.

Digital fundamentals 10th edition powerpoint