In this article, Yingshang Microelectronics memory chip supplier mainly introduces the difference between RAM and SDRAM in ARM in detail. First, it introduces RAM and SDRAM in detail. Finally, it introduces the difference between the two.
RAM Introduction RAM (Random Access Memory), a very important part of the computer’s structure is memory. Memory is used to store programs and data components, for the computer with memory function, to ensure the normal work. There are many kinds of memory, according to its use can be divided into the main memory and auxiliary memory, the main memory referred to as memory, memory plays a decisive role in the computer, generally use semiconductor memory unit. Since RAM is the most important part of memory, we usually just call it memory. Memory is the place where programs and data are stored. For example, when we use WPS for document processing, when you type a character on the keyboard, it is saved to memory, and when you choose to save to disk, the data in memory is saved to hard disk.
RAM is one that can read data from and write data from. When the machine is turned off, the data stored in it will be lost. A memory chip (SIMM) is a small piece of circuit board that holds the RAM chips together. It is inserted into the memory slots in the computer to reduce the space taken up by the RAM chips.
SDRAM is introduced
SDRAM synchronous dynamic random access Memory, synchronization refers to the Memory work requires step clock, internal command transmission and data transmission are based on it as the benchmark; Dynamic means that the storage array needs to refresh constantly to ensure that the data is not lost; Random data is not linear sequential storage, but by the specified address of the data read and write. At present, 168 lines of 64bit bandwidth memory are basically SDRAM chips, working voltage of 3.3V voltage, access speed up to 7.5ns, and EDO memory is the fastest 15ns. RAM and CPU are controlled at the same clock frequency, so that RAM and CPU external frequency synchronization, cancel the waiting time, so its transmission rate is faster than EDO DRAM.
What’s the difference between RAM in ARM and SDRAM? RAM includes SRAM. The former is static random access memory, which mainly relies on triggers to store data without refreshing, while the latter is dynamic random access memory, which relies on gate capacitors in MOSFET to store data and needs to refresh constantly to replenishing the released charge. Because a single tube can achieve data storage, integration can be achieved higher, power consumption is lower, more mainstream. It should be noted that DRAM is not as fast as SRAM due to the charging and discharging process of capacitor involved in refresh.
As for SDRAM memory, it is synchronous dynamic random access memory, which belongs to DRAM. Its working process needs the cooperation of synchronous clock, so the influence of different route delay can be not considered to avoid indefinite state. Ordinary DRAM is asynchronous transmission, when accessing data, it must wait for several clocks before operation (considering indefinite state), because it will take more time and affect the data transmission rate. As the clock frequency continues to increase, the limitation of this bottleneck will become more and more obvious, and the advantages of SDRAM will be more reflected.