Draiver sd needs updating plase use bus tupe methods
One key disadvantage of flash memory is that it can only endure a relatively small number of write cycles in a specific block.
The individual flash memory cells exhibit internal characteristics similar to those of the corresponding gates.Multi-level cell (MLC) devices, including triple-level cell (TLC) devices, can store more than one bit per cell.The floating gate may be conductive (typically polysilicon in most kinds of flash memory) or non-conductive (as in SONOS flash memory).However, the I/O interface of NAND flash does not provide a random-access external address bus.Rather, data must be read on a block-wise basis, with typical block sizes of hundreds to thousands of bits.NOR flash continues to be the technology of choice for embedded applications requiring a discrete non-volatile memory device.
The low read latencies characteristic of NOR devices allow for both direct code execution and data storage in a single memory product.
Its endurance may be from as little as 100 erase cycles for an on-chip flash memory, NOR-based flash was the basis of early flash-based removable media; Compact Flash was originally based on it, though later cards moved to less expensive NAND flash.
NAND flash has reduced erase and write times, and requires less chip area per cell, thus allowing greater storage density and lower cost per bit than NOR flash; it also has up to 10 times the endurance of NOR flash.
In addition to being non-volatile, flash memory offers fast read access times, although not as fast as static RAM or ROM.
Its mechanical shock resistance helps explain its popularity over hard disks in portable devices, as does its high durability, ability to withstand high pressure, temperature and immersion in water, etc.
While EPROMs had to be completely erased before being rewritten, NAND-type flash memory may be written and read in blocks (or pages) which are generally much smaller than the entire device.