Introducing memory, what are the storages?

Memory, also known as memory, is an electronic device made of semiconductor technology to store data. The data of electronic circuits is stored in binary, and each memory cell is called a memory element or cell.

Classify. According to the relationship between storage capacity and power supply, it can be divided into two categories:

Volatile memory: refers to the fact that when the power supply** is interrupted, the data stored in the memory will disappear, generally known as RAM. There are two main types.

DRAM: Dynamic Random Access Memory.

SRAM: Static Random Access Memory.

Non-volatile memory: Even if the power is interrupted**, the data stored in the memory does not disappear and can be read when the power is re-powered.

ROM (read-only memory).

A type of memory that can only read data. In the manufacturing process, the data is burned into the circuit with a special mask, and the content of the data cannot be changed after it is written, so it is sometimes called mask ROM. This memory is inexpensive to manufacture and is commonly used in computers to boot up.

PROM (Programmable ROM).

There is a determinant wire inside, which is burned off by an electric current as needed and written into the required data, but can only be written once.

EPROM (Erasable Programmable Read Only Memory).

The data can be programmed and written by high voltage, and the line is erased under ultraviolet light, so that the data can be emptied and can be reprogrammed. A quartz transparent window is usually reserved on the package housing for convenience**.

OTPROM (One Time Programmable Read Only Memory)

The writing principle is the same as eprom, but in order to save costs, it is no longer erased after programming the write, so there is no transparent window.

EEPROM (electrically erasable programmable read only memory).

Similar to EPROM, but erasing is done using a high electric field, so there is no need for a transparent window.

Flash memory

Each memory cell in this memory has a control gate and a floating gate, which can be programmed by changing the critical voltage of the floating gate with a high electric field.

A memory is an instrument that stores data and has a storage medium inside.

On the medium, there are usually 0 and 1, that is, the real data, he looks at whether the medium inside it is changed to 1, the other is 0, and then through other decoding systems to become ** or text and other data you want.

At present, there are magnetic storage like magnetic tapes, as well as new flash memory such as U disks.

The storage medium that makes up the memory is mainly semiconductor devices.

and magnetic materials. The smallest unit of storage in memory.

It is a bistable semiconductor circuit or a CMOS transistor or a memory element of a magnetic material that can store a binary**. A memory cell is made up of several storage elements, and then a memory is formed by many memory cells.

There are several different ways to classify memory according to the properties of the stored material and how it is used.

1 Classified by storage medium.

Semiconductor memory: A memory composed of semiconductor devices.

Magnetic surface memory: A memory made of magnetic materials.

2 Categorized by storage method.

RAM.

The contents of any cell can be accessed randomly, regardless of the time of access and the physical location of the cell.

Sequential memory: It can only be accessed in a certain order, and the access time is related to the physical location of the storage cell.

3 Classification by read/write function of memory.

Read-only memory.

ROM): A semiconductor memory that is fixed and can only be read and not written.

Random read-write memory (RAM): Semiconductor memory that can be read and written to as well as both.

4 Categorized by the storability of information.

Non-permanent memory: Memory that disappears when the power is off.

Permanent memory memory: A memory that can still hold information even after a power failure.

5 Press on the computer system.

The role of the classification is classified.

Main memory. Memory): Used to store active programs and data, with high speed, small capacity, and high price per bit.

Secondary memory.

External memory): Mainly used to store currently inactive programs and data, it is slow, large capacity, and low price per bit.

Buffer memory: It mainly acts as a buffer for two parts with different working speeds.

There are many storage devices, such as USB flash drives, hard disks, memory cards, etc.

Memory is a memory device used in modern information technology to keep the letter and filial piety. In a digital system, any binary data can be stored in memory.

In integrated circuits, a circuit with storage function that does not have a physical form is also called memory, such as RAM, FIFO, etc.

In the system, a storage device with a physical form is also called memory, and all the information in the computer, including the input original data, computer programs, intermediate running results and final running results, are stored in the memory.

There are two basic types of reservoirs: ROM and RAM.

ROM (Read-Only Memory): In a ROM, read-only data is pre-recorded and cannot be moved. ROMs are not easy to lose, that is, they retain their contents regardless of whether the computer is powered on or off.

Most PCs have small ROMs and are mainly used to store critical programs, such as those used to start the Calculating Calculator. In addition, ROMs are also used in calculators and peripherals, such as laser printers, where fonts are stored. There are also some extended variables in the ROMs, such as programmable read-only memory (PROM), which uses a dedicated PROM programmer to write data on a blank chip.

RAM (Random Access Memory): The contents of this memory can be accessed (read, write, and moved) in any order and out of order. This is in contrast to time-series memory devices, such as tapes, records, etc., where the mechanical movement of the storage medium forces the computer to access data in a fixed order.

RAM is usually responsible for the main storage tasks in a computer, such as the storage of dynamic information such as data and programs. Common formats for RAM include: SRAM (Static RAM) and DRAM (Dynamic RAM).

RAM ICs are usually assembled as sockets. Common standard slot types include: SIMM (Single In-Line Memory Module) slot and DIMM (Dual In-Line Memory Module) slot.

In addition, there are memory types such as Flash Memory, NVRAM, and EEPROM, which are obtained by combining RAM and ROM features.

Function: 1. In the memory of the computer, the program and other data to be referenced by the microprocessor when performing calculations, such as the calibration data of the vehicle. For a CPU, a program is a set of instructions or specifications that a computer must execute.

The information contained in the program tells the microprocessor when to acquire the input signal, how to process the input signal, and what to do after the signal processing is complete. Microprocessors work with memory in two ways: by reading information in memory or by changing the information in memory by writing people or storing new information.

2. Memory contains many different storage units. You can think of an information storage unit as a folder inside a filing cabinet, and within each storage unit there is a piece of information. Each memory cell is given an address.

An address can be likened to a number or letter written on a folder. Each address is written in the form of binary codes, and these binary codes all start with 0 and are encoded sequentially.

3. When the engine is running, the computer receives a large amount of information from various sensors, and the computer cannot process all the information at once. In some cases, the computer needs to receive input from a number of sensors, which is only needed for the computer to make a large number of decisions. In this case, the microprocessor specifies the address of the memory and sends information to that address, thus writing the input information from these sensors to the memory.