Nowadays, affected by the development of 5G and the epidemic, the rapid development of the smartphone and tablet computer industry has triggered higher requirements for storage hardware. Multimedia playback, high-definition camera, GPS, various applications and the development trend of slim and compact appearance require storage hardware with high capacity, high stability and high reading and writing speed, while the storage chip needs to occupy a smaller space in the motherboard .
In the 1980s, Japan published the NAND Flash structure, emphasizing lower cost per bit, higher performance, and can be easily upgraded through an interface like a disk. Because the chip capacity of NAND Flash is larger than that of NOR, it is more like a hard disk, and the speed of writing and erasing data is much faster than that of NOR, so it was mostly used in minicomputers to store data at that time. At present, it has been widely used in various storage devices, which can store codes and data.
The memory cell of NAND Flash has grown from the original SLC to MLC in 2003. So far, SLC has faded out of the mainstream market, and the mainstream memory cell is moving from MLC to TLC. The development of nano-process technology and memory cells has enabled the same size of chips to have higher density and more memory cells. While the capacity of Flash can increase rapidly, the cost of unit storage capacity has also been greatly reduced.
However, the performance of NAND Flash continues to decline with the development of the mainstream trend of nano-process and storage technology. The erasable life is short, the error probability is high, the read and write speed is slow, and the stability is poor. The embedded memory chip eMMC can make up for the gap between market demand and the development of NAND Flash.
eMMC (Embedded Multi Media Card) adopts a unified MMC standard interface, encapsulating high-density NAND Flash and MMC Controller in a BGA chip. In view of the characteristics of Flash, the product has already included Flash management technology, including error detection and correction, flash average erasing, bad block management, power failure protection and other technologies. Users do not need to worry about changes in flash wafer manufacturing processes and processes within the product. At the same time, a single eMMC chip saves more space inside the motherboard.