what is meant by synchronous dynamic random access memory (sdram)?course hero

What is synchronous RAM?

Synchronous dynamic random access memory (SDRAM) is dynamic random access memory (DRAM) with an interface synchronous with the system bus carrying data between the CPU and the memory controller hub. SDRAM has a rapidly responding synchronous interface, which is in sync with the system bus. SDRAM waits for the clock signal before it responds to control inputs.

What is SDRAM in computer science?

SDRAM is improved DRAM with a synchronous interface waiting for a clock pulse before it responds to data input. SDRAM uses a feature called pipelining, which accepts new data before finishing processing previous data. A delay in data processing is called latency. DRAM technology has been used since the 1970’s.

How many nanoseconds does SDRAM use?

DDR uses both edges of the clock. SDRAM has a 64-bit module with long 168-pin dual inline memory modules (DIMMs). SDRAM access time is 6 to 12 nanoseconds (ns). SDRAM is the replacement for dynamic random access memory (DRAM) and EDO RAM.

Why is SDRAM slower than EDO?

In the beginning SDRAM was slower than burst EDO DRAM because of the extra logic features. But the benefits of SDRAM allowed more than one set of memory, which increased the bandwidth efficiency. With the introduction of DDR, SDRAM quickly began to fade out of use because DDR was cheaper and more cost effective.

Why did SDRAM fade out?

With the introduction of DDR, SDRAM quickly began to fade out of use because DDR was cheaper and more cost effective. The SDRAM used a 168-pin while the DDR module used a 184-pin. SDRAM modules used a voltage of 3.3V and DDR used 2.6V, producing less heat.

What is the difference between SDRAM and DDR?

There are three significant characteristics differentiating SDRAM and DDR: The main difference is the amount of data transmitted with each cycle, not the speed. SDRAM sends signals once per clock cycle. DDR transfers data twice per clock cycle. (Both SDRAM and DDR use the same frequencies.) SDRAM uses one edge of the clock.

How many times does a clock signal change?

This cycle is called rise and fall. A clock signal changes two times per transfer, but the data lines change no more than one time per transfer. This restriction can cause integrity (data corruption and errors during transmission) when high bandwidths are used. SDRAM transmits signals once per clock cycle. The newer DDR transmits twice per clock cycle.

What is double data rate SDRAM?

DDR SDRAM has the features of SDRAM, but with twice the data transmission frequency. That’s why it’s called “double data rate SDRAM.”

What does DRAM do?

All RAM types, including DRAM, are a volatile memory that stores bits of data in transistors. This memory is located closer to your processor, too, so your computer can easily and quickly access it for all the processes you do.

What does DRAM mean?

DRAM stands for “dynamic random access memory, ” and it’s a specific type of RAM (random access memory). All computers have RAM, and DRAM is one kind of RAM we see in modern desktops and laptops. DRAM was invented in 1968 by Robert Dennard and put to market by Intel® in the ‘70s.

What are the different types of RAM?

It may seem like we’ve given you a lot of information. Fortunately, we can sum everything up in a handful of easy-to-remember points: 1 DRAM is a form of RAM, and it has several types within its category. 2 DRAM is volatile, like all RAM, so it can’t hold data without power. 3 DRAM is fast and comes in different speeds and latency options. Look for a higher speed (MHz) number and a lower latency (CL) number for the best results. 4 Most DRAM is found in DDR4 products, like those featured in HP desktop PCs and laptops. Look for the most updated generation of DDR memory; it’s reliable and affordable.

Why is latency important?

Latency is important, too. A bigger number doesn't tell the whole story, however. Latency, or the time it takes for DRAM to work, also impacts the DRAM speed. This brief pause varies by product, and even a fraction of a second can add up over time when your computer processes thousands of read/write requests per second.

Why is RAM considered volatile?

RAM provides a way for the computer to use, rewrite, and temporarily save this data and code in real-time. Because the transistors need electricity to work, however, anything stored here disappears when you turn your PC off. That's why it's considered “volatile.”.

What is volatile RAM?

All RAM is volatile, which means any data that’s read or written is lost when the computer powers down. If you’re working on a project and don’t want to lose data from an unexpected power outage, then don’t rely solely on RAM. Instead, use long-term memory like an SSD or HDD.

Overview

History

Timing

Control signals

Construction and operation

Command interactions

Burst ordering

Mode register