(electronic chip) memory term explanation

RAM:
Random access memory. Each memory unit can be accessed easily and quickly. In general, RAM refers to any fast, writable volatile memory.

ROM: Read-only memory. Once written, the stored content cannot be changed. In general, ROM refers to a non-volatile memory that is not easily written.

Standard: Read Only Memory Chinese: Read-only memory read-only memory. The contents of this memory will not be changed under any circumstances. The computer and the user can only read the instructions stored here and use the data stored in the ROM. Data, but cannot be changed or stored. The ROM is stored on a non-volatile chip, that is, even if the contents memorized after the shutdown can still be saved, this kind of memory is often used to store a program or a system program of a specific function. The ROM stores instructions for activating the computer. At startup, the ROM provides a series of instructions to the central processing unit for testing. In the initial test, the location of the RAM is checked to confirm its ability to store data. In addition, other electronic components including the keyboard, the timer circuit, and the CPU itself are also included in the test of the CPU.

DRAM:

Dynamic RAM. This memory must be dynamically refreshed periodically, otherwise the memory cell will lose memory data due to discharge.

EPROM:

Electrically programmable ROM. It can be written using a specific device and can be erased by UV.

Standard: Erasable Programmable Read-Only Memory Chinese: Ultraviolet Erasable Read-Only Memory Non-volatile memory. It does not require power to maintain its contents, making it ideal for use as a basic input/output system (BIOS) in hardware. Allows the user to reuse the program with UV light eliminated. This kind of memory does not support the line modification data.

EEPROM: Electrically Erasable Programmable ROM. Erasing with electricity instead of erasing with ultraviolet light like EPROM can be written using a microcontroller. Standard: Electrically Erasable Programmable Read-Only Memory Chinese: Electronically Erasable Read-Only Memory Non-volatile memory. After the power is removed, the stored data (Data) still exists. When a voltage is applied to a special pin and a corresponding command is output at the same time, internal data can be erased. Typically used in televisions, air conditioners, stores user-set parameters. This kind of memory supports re-line modification of data. Before writing data every time, it must be ensured that the writing unit is erased. The time for writing a data is about 2-10ms. Single-byte cell erase is supported.

Flash: An easy-to-write, but slow, non-volatile memory.

Chinese flash memory Non-volatile memory. It is currently the largest memory in non-volatile memory that can be rewritten online. Supports the modification of data by another line, and the speed of writing data is improved by one order of magnitude compared with EEPROM. Flash is used for large-capacity data and program storage, such as electronic dictionary libraries, solid state drives, and operating systems on PDAs.

PROM: Programmable ROM. Only write once, true read-only memory.

SRAM: Static RAM. Static means that once written, data can be maintained as long as there is power. SRAM manufacturing method is different from Dynamic Random Access Memory (DRAM). Each bit uses 6 transistors. It does not need to constantly refresh the transistor cycles to keep data from being lost, and its access time is shorter. The circuit is simple, but the manufacturing cost is high, and it is difficult for a single chip to do DRAM-like capacity.


SDRAM: Synchronous DRAM. Synchronous means that the data is controlled by the clock signal Access Standard: Synchronous Dynamic RAM Chinese: Synchronous Dynamic Random Access Memory The operating clock of the SDRAM is synchronous with the microprocessor so it can be faster than the EDO DRAM. , using 3.3V voltage (EDO DRAM 5V), 168 pins, can also match the external clock of the CPU (CPU), and have different specifications of 66 and 100MHz, 100MHz specifications are known to everyone PC100 memory (Memory).

RDRAM Standard: Rambus DRAM Chinese: Rambus DRAM This is a type of memory that is mainly used for image acceleration. It provides a transmission rate of 1000 Mbps. It operates without interruption, compared to the dynamic random access memory (DRAM). 200mbps is faster, and of course the price is more expensive than DRAM. Although RDRA cannot completely replace existing memory, it can replace DRAM and static random access memory (SRAM) because of the bus speed requirement. The operating speed of SDRAM is 100 Hertz (Hz). Manufacturers can display RDRAM up to 600MHz. The memory is only 8 or 9 bits long. If RDRAM is used side by side, the bandwidth can be greatly increased and the memory can be increased. Increase to 32 or 64 bits.

FeRAM

Standard: Ferroelectric random access memory: Ferroelectric memory Compared to other types of semiconductor technology, ferroelectric memory has some unique features. The traditional mainstream semiconductor memory can be divided into two categories - volatile and non-volatile. Volatile memory includes static random access memory (SRAM) and dynamic random access memory (DRAM). Both SRAM and DRAM lose their saved data when they are powered down. RAM-type memories are easy to use and perform well, but they also lose their saved data in the event of a power loss.

Non-volatile memory does not lose stored data in the event of a power loss. However, all mainstream non-volatile memories are derived from read-only memory (ROM) technology. As you can guess, what is called read-only memory is certainly not easy to write, but in fact it cannot be written at all. All memory developed by ROM technology has the difficulty of writing information. These technologies include EPROM (almost obsolete), EEPROM and Flash. These memories not only have slow write speeds, but also can write only a limited number of times and consume large amounts of power during writing.

The ferroelectric memory is compatible with all functions of the RAM and, like the ROM technology, is a non-volatile memory. Ferroelectric memory has built a bridge across the two types of storage - a non-volatile RAM.

MCU

The MCU (Micro Controller Unit), also known as a Single Chip Microcomputer, is simply referred to as a single chip microcomputer. It refers to the appearance of a large-scale integrated circuit and its development. The CPU, RAM, ROM, timing devices, and many more The I/O interface is integrated on a chip to form a chip-level computer.