u-boot中的bank

在u-boot中，使用flinfo命令查看flash信息，会看到bank信息。例如，在板子上输入

$ help erase
erase - erase FLASH memory

Usage:
erase start end
    - erase FLASH from addr 'start' to addr 'end'
erase start +len
    - erase FLASH from addr 'start' to the end of sect w/addr 'start'+'len'-1
erase N:SF[-SL]
    - erase sectors SF-SL in FLASH bank # N
erase bank N
    - erase FLASH bank # N
erase all
    - erase all FLASH banks

$ flinfo

Bank # 1: CFI conformant flash (16 x 16) Size: 64 MB in 512 Sectors
  AMD Standard command set, Manufacturer ID: 0x01, Device ID: 0x227E
  Erase timeout: 4096 ms, write timeout: 1 ms
  Buffer write timeout: 3 ms, buffer size: 64 bytes

  Sector Start Addresses:
  00000000   RO   00020000        00040000   RO   00060000   RO   00080000
  000A0000        000C0000        000E0000        00100000        00120000
  00140000        00160000        00180000        001A0000        001C0000
  001E0000        00200000        00220000        00240000        00260000
  00280000        002A0000        002C0000        002E0000        00300000

对于bank，在上，这么解释：

Technically speaking, a bank is an area of memory implemented by one or more memory chips that are connected to the same chip select signal of the , and a flash sector or erase unit is the smallest area that can be erased in one operation.

For practical purposes it is sufficient to remember that with flash memory a bank is something that eventually may be erased as a whole in a single operation. This may be more efficient (faster) than erasing the same area sector by sector.

bank仅仅只是同一个片选信号选中的一块内存区域而已。或许是单块内存芯片中的一部分，或许是多个内存芯片组合而成。
方便之处，在于以后删除多个sector时，可以选中同一个bank，删除该bank即可。

有些flash的datasheet中也涉及到bank这个名词，道理同上所述。片选信号不同，bank号码亦不同。