SRAM is the abbreviation of English static RAM, it is a kind of memory with static log access function, it can save the data stored inside it without the need of refreshing circuit. Does not need to refresh the circuit like DRAM memory, every once in a while, fixed to the DRAM refresh charge once, otherwise the internal data will disappear, so SRAM has a high performance, but SRAM also has its disadvantage, that is, its integration, the same capacity of DRAM memory can be designed to a smaller volume, But SRAM needs a lot of volume, so on the motherboard SRAM memory to occupy part of the area, on the motherboard which is SRAM.
One is the cache placed between the CPU and main memory, which has two specifications: one is fixed on the motherboard cache (cache Memory), and the other is the coast (cache on A Stick) expansion cache that is plugged into the card slot. In addition, in the CMOS chip 1468L8 Circuit, its interior also has the small capacity 128 byte SRAM, stores the configuration data which we set up. There is also in order to speed up the transfer of data within the CPU, since 80486CPU, in the CPU has also designed a cache, so the Pentium CPU on the so-called L1 cache (first-level cache) and L2cache (level two cache) of the term, General L1 Cache is built inside the CPU, L2 cache is designed outside the CPU, but Pentium Pro L1 and L2 cache at the same time designed in the CPU's interior, so Pentium Pro volume is larger. The newest Pentium II also moves the L2 cache to a black box outside the CPU core. SRAM is obviously fast, do not need to refresh the *, but there are other disadvantages, that is, high prices, large volume, so the motherboard can not be used as a larger main memory. Its characteristics are summarized as follows:
Advantages, energy-saving, fast, do not need to match the memory refresh circuit, can improve the overall efficiency.
Disadvantages, low integration, the same volume of large, and higher prices, a small number of critical systems to improve efficiency.
SRAM-Used systems:
A cache between 0CPU and main memory.
0CPU internal L1/L2 or external L2 cache.
0CPU Coast cache for external expansion.
0CMOS 146818 Chip (Rt&cmos SRAM). The relationship and difference between DRAM, SRAM and SDRAM
DRAM, dynamic random access memory, requires constant refresh in order to save data.
and is the row and column address multiplexing, many have page patterns.
SRAM, static random access memory, power in case, no need to refresh, data
Will not be lost, and, generally, is not a row-and-column address multiplexing.
SDRAM, synchronized dram, that is, data read and write requires a clock to synchronize.
DRAM and SDRAM have larger capacity than SRAM due to the realization of process problems.
But read and write faster than SRAM,
But now, SDRAM speed is also very fast, the clock seems to have
150 trillion of them. Then the reading and writing period is less than 10ns. SDRAM, although high frequency, but the actual throughput rate to discount. Taking PC133 as an example, it's
Clock cycle is 7.5ns, when CAs latency=2, it takes 12 cycles to complete 8 bursts
Read operation, 10 cycles to complete 8 burst write operations. However, if you are accessing the bank in alternate ways,
SDRAM can complete a read and write operation (excluding the refresh operation, of course) in each cycle.
In fact, the current mainstream high-speed memory is Ssram (synchronous SRAM) and SDRAM (synchronous DRAM).
At present, it is convenient to buy the maximum capacity of Ssram is 8mb/, the maximum working speed is 166MHz;
can easily buy the SDRAM maximum capacity is 128mb/slice, the maximum working speed is 133MHz.
Although many foreign companies on the Web site can see better performance of the product introduction, but those
is basically a concept product that has not yet been put into production:p
One is static, one is dynamic, and static is the use of bistable triggers to save information, and dynamic is the use of electrons, or when the refresh to maintain.
Memory (that is, random ram) can be divided into static random memory SRAM, and dynamic random memory dram two kinds. We often say "memory" refers to DRAM. But the SRAM everybody but touches very little.
SRAM is actually a very important memory, it is widely used. SRAM is very fast and can maintain data integrity while fast reading and refreshing. SRAM internal use is the form of bistable circuit to store data. So the circuit structure of SRAM is very complex. SRAM, which creates the same capacity, is much more expensive than DRAM. That is why its development has been limited. So the current SRAM is basically only used for the first level cache inside the CPU and the built-in level two cache. There are only a small number of network servers and the ability to use SRAM on routers.
