Flash memories will account for $26B in sales in 2010. They are used in all modern digital cameras, camcorders, cell phones, PDAs, music players, home video game machines and computers.
Why is flash so popular? Flash excels in three areas: technical, physical and financial. The technical reasons are (1) nonvolatility–flash memory retains its information for more than 10 years even with no power applied and (2) speed–flash memory is 100 to 1000 times faster than magnetic hard drives. The physical reasons are (1) density–flash memory has 8x as many bits per chip as DRAM, and (2) power–flash memory consumes far less power than magnetic hard drives. In the financial area, flash memory is about 40% of the cost of DRAM on a per bit basis.
Why isn't flash memory used in place of DRAM and magnetic hard drives? Again, there are three areas that hold back flash: reliability, speed and cost. Regarding reliability, flash memories can endure from 5000 to over 100,000 erase/program cycles. That is adequate for many but not all applications. Flash speed is indeed much faster than magnetic hard drives, but programming speed is far slower that DRAMs; much too slow for main memory applications. And flash cost, although lower than DRAMs, is still far above that of magnetic hard drives.
This course discusses all of the above issues, as well as the historical background, physical basis, cell structure, and chip architecture and operation of these omnipresent devices. You will learn and understand hot electron injection, Fowler-Nordheim tunneling, NOR and NAND array structures and operation, multi-level storage and error correction coding. The flash memory market, including applications and major producers, are explored; and two major portions of that market, flash memory cards and solid state drives, are examined in detail.
This course builds on, but is independent of Memories in Computers–Part 1. No high-level math is required.
