#HOW TO USE NAND X HOW TO#

The number in the process technology represents the distance from source to drain. In order to reduce the cost per bit and expand the capacity of SSD, manufacturers first think of improving the process technology, for example, from the early 50nm to the current 16/15nm process nodes. In this part, I will explain the process technology to you. Since the invention of the NAND flash in 1986, the manufacturers have made a lot of great progress in NAND flash technology, such as the improvement of the process technology, 3D NAND, MLC, TLC and QLC. However, if the higher voltage and the lower voltage are close, especially when too many erasing times lead to poor insulation performance, it is very likely that electrons enter adjacent memory cells. Thus, electrons can be easily injected into the floating gates of the cells on the written page. When a page is written, a higher voltage will be applied to the control electrodes of cells on the page while a lower voltage will be applied to the control electrodes of the cells on other pages that are not written. On the other hand, the more times you erase blocks, the worse the insulation effect, and the easier it is for electrons to enter the floating gate. When a page is read, a voltage Vref is applied to the control electrodes of cells on the page while the control electrodes of the cells on other pages is applied with a relatively larger voltage Vpass, which may create a stronger electric field to draw some electrons into the floating gate of the cells on the pages that are not read (program data), resulting in data error. Each cell usually stores one bit of data (a cell can also store more than one bit of data and I will explain to you later). The principle is as follows:Д®ach page has a space around 4KB or 8KB.

#HOW TO USE NAND X HOW TO#

If you worry about your SSD's life, you can read the following post to know how to prolong your SSD's life.ДЄs the flash memory is read multiple times, the contents of adjacent memory cells in the same block will change (become a write operation).

The electrons in the floating gate cannot come out ( erase failure).

The electrons in the floating gate can easily come out ( data retention issue).

Electrons can't enter the floating gate ( write failure).

Because once the number of P/E cycles is exceeded, the following situations are most likely to occur: When this number is exceeded, the block may become unusable. Therefore, write amplification cannot be avoided.Д®ach NAND block has a limit on the number of times that it can be erased. On the other hand, data is usually written at random and non-continuous locations whether to modify or write data, erasure is required. However, when you erase data, the unit is block. When you write or read data, the unit is page. In general, a NAND flash chip has multiple LUNs (Logic Unit Number) each LUN has multiple planes each plane has thousands of blocks each block has hundreds of pages. NAND flash also has its inherent disadvantages like the following ones: 1. Through this charge manner, data can be stored in each NAND memory cell.Д«ut when power is detached from NAND flash memory, the floating-gate transistor will provide an extra charge to the memory cell, keeping the data.

When you program one cell (write data), a voltage charge is sent to the control gate, making electrons enter the floating gate. Both gates help control the flow of data. NAND memory cells are made with two types of gates: control and floating gates.

How to use nand x