SRAM(Static Random Assessable Memory)-where the word static indicates that it, does not need to be periodically refreshed, as SRAM uses bistable latching circuitry (i.e., flip-flops) to store each bit. Each bit is stored as a voltage.Each memory cell requires six transistors,thus giving chip low density but high speed.However, SRAM is still volatilein the (conventional) sense that data is lost when powered down.
Disadvantages are more expensive and also consumes more power than DRAM.
In high speed processors (such as Pentium), SRAM is known as cache memory and is included on the processor chip.However high-speed cache memory is also included external to the processor to improve total performance.
DRAM(Dynamic Random Assessable Memory)- Its advantage over SRAM is its structural simplicity: only one transistor (MOSFET gates) and a capacitor (to store a bit as a charge) are required per bit, compared to six transistors in SRAM. This allows DRAM to reach very high density.Also it consumes less power and is even cheaper than SRAM (except when the system size is less than 8 K) .
But the disadvantage is that since it stores bit information as charge which leaks;therfore information needs to be read and written again every few milliseconds.This is known as refreshing the memory and it requires extra circuitry,adding to the cost of system.
DRAM:when the select line is high and the transistor is turned on , the capacitor is charged on the same voltage as in data line.
secondly,When the capacitor stores in logic one and discharge in logic zero.
Lastly,when the charge is complete , select line is turned to logic zero turning off the transistor and also cutting off the capacitor and charge is retained at logic one.
SRAM(static random access memmory):---- 1.Transistors are used to make this type of RAM. 2.it is a flip flop. 3.It is faster compared to DRAM. DRAM(dynamic randomaccess memory):---- 1.It store data as charge on capacitor. 2.its need refreshing of charge on the capacotor after every few millisecond. this complicates the design,since it require extra hardware to control refreshing of charge. 3.it contaon more memory cell as compared to SRAM per unit area. 4. Low cost compared to SRAM
Memory cache
sram based anti-fuse
the two main types of RAM are: SRAM- static random access memory which is faster but more expensive it also takes up valuable space. It tends to be used for cache memory and it doesnt have to be periocically refreshed. DRAM- dynamic random access memory, the most common type of RAM, an advantage of DRAM is its structural simplicity.
Refreshed.
That would be DDR-3 memory. Some multi-core systems use DDR-2 memory. Then of course there is cache memory, but that is a variation of SRAM, and it has been used ever since the 386 or 486 machines. Nowadays, cache memory is not in discrete chips, but a part of the processor. Placing the cache memory and memory controller on the CPU die greatly improves the throughput.
Conventional DRAM, of the type that has been used in PCs since the original IBM PC days, is said to be asynchronous. This refers to the fact that the memory is not synchronized to the system clock. A memory access is begun, and a certain period of time later the memory value appears on the bus. The signals are not coordinated with the system clock at all, as described in the section discussing memory access. Asynchronous memory works fine in lower-speed memory bus systems but is not nearly as suitable for use in high-speed (>66 MHz) memory systems. A newer type of DRAM, called "synchronous DRAM" or "SDRAM", is synchronized to the system clock; all signals are tied to the clock so timing is much tighter and better controlled. This type of memory is much faster than asynchronous DRAM and can be used to improve the performance of the system. It is more suitable to the higher-speed memory systems of the newest PCs.
dram is material gives sound and sram is the sound itself
sram and dram
DRAM has a lower price. Further details below:
DRAM and SRAM
Dynamic Random Access Memory contents need to be continuously refreshed. When its contents are being refreshed, memory can not be read from nor write to. Another point to note is that DRAM is cheap to manufacture (This could be the only advantage it has to SRAM).Where as in Static Random Access Memory, memory need not to be continuosly refreshed and therefore memory can be accessed at any time. SRAM is expensive to manufacture.
SRAM DRAM SDRAM XRAM is not a form of RAM.
SRAM DRAM SDRAM XRAM is not a form of RAM.
DDR and DDR2
---SRAM--- Static random access memory (SRAM) is a type of semiconductor memory where the word static indicates that it, unlike dynamic RAM (DRAM), does not need to be periodically refreshed, as SRAM uses bistable latching circuitry to store each bit. SRAM exhibits data remanence, but is still volatile in the conventional sense that data is eventually lost when the memory is not powered. The term SDRAM, which stands for synchronous DRAM, should not be confused with SRAM.
•Dynamic cell (DRAM) -Simpler to build, smaller -More dense -Less expensive -Needs refresh -Larger memory units •Static (SRAM) -Faster -Cache
This is incorrect. DRAM is a digital device, and so is SRAM. DRAM and SRAM serve the same functions- temporary storage space (or random access memory, hence 'RAM') in different ways. DRAM data is typically refreshed every so often, uses more power than SRAM and is much slower, but also much cheaper and easier to manufacture in huge sizes. SRAM, such as the cache on CPUs, is much smaller and faster, and stores data until it is cleared or the computer is turned off (and in some cases, even without power) but is extremely expensive.
SRAM (Static RAM) and DRAM (Dynamic RAM)