Flash简介

看了3个主帖:

• Nand Flash - 博客园
• NAND Flash Memory Technology: The Basics of a Flash Memory Cell by Zachary Painter
• Technical Note NAND Flash 101: An Introduction to NAND Flash and How to Design It In to Your Next Product

又从别的地方抄了点。高纯度的硅棒切成圆片，叫做wafer. It is round, with specifications of 6 inches, 8 inches, and 12 inches etc. wafer: 用作圣餐的小圆饼。

每个wafer可以切出若干个die: 硬模, a Metal block used to press or cut something into a particular shape. The intact, stable die with sufficient capacity is removed (from the wafer) and packaged to form a chip.

die上刻电路，最后package封装。                   i7-5960X De-Lidded (开盖)

  

flash := 1 or 2 planes

plane := block plane :-) plane由block们组成

Blocks usually contain around 128 pages. Pages are the smallest units that can be programmed (or written to). 软件工程师倾向于认为page比block大。如memory page 4KB/8KB，好像还有32KB的，一个block几百个字节。

There are two main types of Flash memory: nor and NAND. Both types integrate a grid system of Flash memory cells that are wired together.

在nor Flash里，Cells are organized in an array of rows and columns. In both nor and NAND configurations, word lines are the wires connecting the
rows, and bit lines are the wires connecting the columns. x86和Windows有WORD, DWORD(Double Word)的叫法。似乎我们可以把bit看作字母，某种语言里的词由bit组成，都是定长的，比如16。或者说word是纵坐标y，bit是横坐标x。

NAND Flash, on the other hand, links an entire cell column by running the bit line through each cell, bypassing the need for an extra bit line connector on the side.

  

Due to their wiring configurations, nor offers better read speeds and random access capabilities; NAND offers better write/erase capabilities with a cheaper cost per bit, so it’s better suited for the data demands of SSDs, Flash Drives, and Flash Memory Cards. 好像nor可以单独寻址每一个Cell，而NAND可以也只能一次搞一串。

NAND和nor的Cell也不一样。串联和并联一个相当于and，另一个相当于or。两把锁串起来开一把就行，并起来得都开才行，电路里好像是反的。nand和nor分别是and和or的结果再not下，和高/低电平, 0/1, 导通...有关，弄不好就又说反了，所以不说，大概其吧。:-) nor和NAND的起名来源于Cell的结构，分别对应逻辑门电路中的nor gate和NAND gate.