Flash session 2: What is Flash Memory?
By Avi Klein, Senior
Principal Engineer, Memory Technology Strategy
Video | Duration: 11:46 min |
This session focuses on NAND flash memory, why it has become so
popular for use in electronic devices, and the challenges designers
face to implement advanced NAND technologies that provide
increasingly higher capacities cost effectively, while maintaining
high levels of flash reliability and performance.
Chapter 1: Introduction
Introduces the topics to be discussed in this session. Describes
the difference between volatile and non-volatile memory (NVM), and
the applications for non-volatile memory over the ages, beginning
with paper all the way to flash memory.
Chapter 2: Types of Non-Volatile Memory
Defines non-volatile memory (NVM) and describes the various types.
Focuses on the characteristics of NOR and NAND flash, the
applications for which both of these types of non-volatile memory
are best suited, the differences in their architecture and the
impact of these differences on performance.
Chapter 3: Importance of Memory to Users
Discusses why users care about what memory their devices use, in
particular issues of data retention and endurance. Describes how
they affect data reliability and the memory's lifespan.
Chapter 4: NAND Die and Architecture: 2002 to
Today
Presents generations of NAND dies and how they have evolved from
2002 to the present. Introduces terms associated with NAND die,
including memory array, planes, sense amps, row decoders, control
signals and I/O pads. Describes the NAND flash memory array,
defining flash memory terms such as bit lines, word lines, memory
cell, pages and blocks, and also basic computer storage terms such
as bit, byte, memory cell and level.
Chapter 5: Single Level Cell and Multi Level
Cell
Defines Single Level Cell (SLC) technology, and discusses how its
cost limitations in high capacities gave rise to Multi Level Cell
(MLC) technology. Introduces the challenges of MLC technology to
store increasingly more data in less silicon. Discusses the need
for a system approach to manage MLC flash. Reviews the benefits of
NAND flash - higher capacity, lower cost, smaller form factor - and
the impact of technological advances on performance and
reliability.
Chapter 6: Summary
Reviews the subjects discussed in the presentation, including the
types of memory, why NAND has become so popular, the challenges
designers face to maintain high performance and reliability when
using MLC technology, and the need for a system approach to meet
these challenges.
Keywords:
Volatile memory, Non-volatile memory, Data retention, Data
reliability, Endurance, EPROM, EEPROM, NOR flash, NAND flash, NAND
die, Memory array, Memory cell, Memory plane, Sense amps, Row
decoders, Control signals