Introduction
Dynamic Random Access Memory ( Dynamic Random Access Memory , DRAM ) is one Semiconductor memory, the main principle is to use the amount of storage charge in the capacitor to represent a binary bit (bit) 1 or 0. Since the transistors in reality will have a leakage current, the amount of charge stored on the capacitor is not sufficient to determine data, resulting in data damage. Therefore, for DRAM, periodically charging is an unavoidable element. Since this requirement is refreshed, it is called a "dynamic" memory. Relatively, the static memory (SRAM) will not lose memory as long as the data is deposited.
Compared to SRAM, the advantage of DRAM is that the structure is simple - each bit of data requires only one capacitor to handle it with a transistor, compared to a bit on SRAM usually requires six transistors. . This, the DRAM has a very high density, and the capacity of the unit volume is less costly. But the opposite, DRAM also has a shortcoming of the accessed speed and a large power consumption.
Like most random access memory (RAM), since the data in the presence of DRAM will disappear quickly after the power cut, it belongs to a Volatile Memory device.
Working principle
DRAM typically is arranged in a two-dimensional matrix in a capacitor and a transistor. The basic operating mechanism is divided into read and write (Write), first allowing BitLine (BL) first to charge half of the operating voltage, and then open the transistor to make BL and capacitance to generate charge sharing, if the interior The value of the store is 1, the voltage of the BL is raised by the charge shared to half of the operating voltage. In contrast, if the value of the internal storage is 0, the voltage of the BL is lowered below half of the operating voltage, After obtaining the voltage of the BL, it is determined that the inner value is 0 and 1 after the amplifier is passed. When writing, the transistor is turned on. To write 1, the BL voltage is raised to the operating voltage to store the operating voltage on the capacitor. To write 0, the BL is reduced to 0 volts There is no charge inside the capacitor.
Random Access Memory
Random Access Memory (English: r andom a ccess M Emory, abbreviation: RAM ), also called Main memory , is an internal memory directly exchanged with the CPU. It can read and write at any time (except for refresh, see below), and fast, usually used as a temporary data storage medium for operating systems or other running programs.
Main memory is the main memory inside the computer, used to load a wide variety of programs and data for CPU direct operation and application. Because DRAM has a high cost performance, and the scalability is also good, it is the most important part of today's general computer main memory. In 2014, the main memory used in the production of computers was mainly DDR3 SDRAM, and DDR4 SDRAM in 2016 gradually spread. The pen electric manufacturer such as ASUS and Acer began to replace DDR3L with DDR4 memory in writing.
Related entries
-
memory
-
volatile memory
< Li> -
Dynamic random memory price manipulation
-
SDRAM
Static random access memory