Hello all,
The memory chip can be divided into flash memory and memory. The flash memory includes NAND flash and NOR flash, and the memory is mainly DRAM. To better understand the function of a memory chip, if executing a complete program is likened to manufacturing a product, the memory chip is like a warehouse, and the processor is like a processing workshop.
One way to increase the efficiency of the processing shop is to increase the speed of product manufacturing, which is to increase the performance of the processor. Another way is to shorten the time from the warehouse to the processing shop, and to set up a temporary small warehouse to store the raw materials of the products that are currently specialized in production, which can greatly reduce the manufacturing time. A large warehouse is equivalent to a flash memory in a memory chip, while a small warehouse is equivalent to a memory in a memory chip, which is indispensable to the operation of electronic products. Therefore, they have a high degree of overlap in the application range of products.
Among many semiconductor memories, the largest market size is DRAM and NAND Flash, each with a market size of tens of billions of dollars, of which the market size of DRAM reached $100 billion in 2018. In the era of smartphones, applications of various software increase storage space requirements, and storage space of mobile phones increases rapidly. The NAND flash has become a new favorite of mobile phone storage due to its high-density storage advantages. The eMMC/eMCP used by smartphones are storage solutions that encapsulate the NAND flash and control chip. In terms of application form, NAND flash products include USB flash drives (USBs), flash cards, and solid state drives (SSDs). DRAMs such as embedded storage (eMMC, eMCP, and UFS) are classified into DDR/LPDDR/GDDR and legacy (Legacy/SDR) DRAMs. DDR is short for Double Data Rate SDRAM. Double-rate synchronous dynamic random access memory (DRAM), which is mainly applied to personal computers and servers. Currently, the mainstream DDR standard is DDR4, but DDR5 has been released. It is expected that the penetration rate of LPDDR will increase in the future. LPDDR, also called mobile DDR (mDDR), is mainly used in mobile electronic products. GDDR refers to GraphicsDDR, which is mainly used in the image processing field.
Low Power Double Data Rate SDRAM (Low Power Double Data Rate SDRAM), also called Mobile DDR SDRM (mDDR). LPDDR is a communications standard developed by the JEDEC Solid State Association for low-power memory and is mainly applicable to mobile electronic products. Compared with DDR, LPDDR has lower power consumption.
LPDDR4X and LPDDR4 are used in the memory of mainstream flagship phones. Because they often appear at the same time and have similar names, it is easy to confuse people. In fact, the LPDDR4X is not the next-generation memory of the LPDDR4, but can be regarded as a power-saving optimized version of the LPDDR4.
Compared with LPDDR4, LPDDR4X optimizes memory power consumption and improves memory speed. The storage speed is better, and it's very useful when running large games or recording 4K video, with lower power consumption and faster running and more power saving.
RAM
Random access memory (RAM) is used as a generic term for any memory chip that can be written to and read from which is not a read-only (ROM) chip, as described below. Most RAM is classified as volatile; special types of non-volatile RAM (NVRAM), such as ferroelectric RAM (FRAM), are non-volatile. RAM types include:
Dynamic RAM (DRAM)
Static RAM (SRAM)
Non-volatile RAM (NVRAM)
Ferroelectric RAM (FRAM)
Non-volatile static RAM (NVSRAM)
ROM
Read-only memory (ROM) is more difficult to modify than RAM and is normally used to read permanent data. ROM is typically non-volatile and is used to store frequently-read (but not written/modified) system software. ROM types include:
Programmable ROM (PROM)
Erasable programmable ROM (EPROM)
Electrically erasable programmable ROM (EEPROM)
Flash
Mask ROM
Conclusion
The image below shows the function of both memory types in the hierarchy of a typical computer. Note that ROM is distinct from the computer's hard disk, another type of permanent storage.
Thanks.
