AT45DB021D-MH-SL954(2008) データシートの表示（PDF） - Atmel Corporation
部品番号
コンポーネント説明
メーカー
AT45DB021D-MH-SL954 Datasheet PDF : 52 Pages
| |||
4. Memory Array
To provide optimal flexibility, the memory array of the AT45DB021D is divided into three levels of
granularity comprising of sectors, blocks, and pages. The “Memory Architecture Diagram” illus-
trates the breakdown of each level and details the number of pages per sector and block. All
program operations to the DataFlash occur on a page-by-page basis. The erase operations can
be performed at the chip, sector, block or page level.
Figure 4-1. Memory Architecture Diagram
SECTOR ARCHITECTURE
SECTOR 0a = 8 Pages
2,048/2,112 bytes
SECTOR 0a
BLOCK ARCHITECTURE
BLOCK 0
BLOCK 1
BLOCK 2
SECTOR 0b = 120 Pages
31,744/32,726 bytes
SECTOR 1 = 128 Pages
32,768/33,792 bytes
BLOCK 14
BLOCK 15
BLOCK 16
BLOCK 17
8 Pages
SECTOR 6 = 128 Pages
32,768/33,792 bytes
BLOCK 30
BLOCK 31
BLOCK 32
BLOCK 33
PAGE ARCHITECTURE
PAGE 0
PAGE 1
PAGE 6
PAGE 7
PAGE 8
PAGE 9
PAGE 14
PAGE 15
PAGE 16
PAGE 17
PAGE 18
SECTOR 7 = 128 Pages
32,768/33,792 bytes
BLOCK 126
BLOCK 127
Block = 1,024/1,056 bytes
PAGE 1,022
PAGE 1,023
Page = 256/264 bytes
5. Device Operation
The device operation is controlled by instructions from the host processor. The list of instructions
and their associated opcodes are contained in Tables 15-1 through 15-7. A valid instruction
starts with the falling edge of CS followed by the appropriate 8-bit opcode and the desired buffer
or main memory address location. While the CS pin is low, toggling the SCK pin controls the
loading of the opcode and the desired buffer or main memory address location through the SI
(serial input) pin. All instructions, addresses, and data are transferred with the most significant
bit (MSB) first.
Buffer addressing for the DataFlash standard page size (264 bytes) is referenced in the
datasheet using the terminology BFA8 - BFA0 to denote the 9 address bits required to designate
a byte address within a buffer. Main memory addressing is referenced using the terminology
PA9 - PA0 and BA8 - BA0, where PA9 - PA0 denotes the 10 address bits required to designate
a page address and BA8 - BA0 denotes the 9 address bits required to designate a byte address
within the page.
For the “Power of 2” binary page size (256 bytes), the Buffer addressing is referenced in the
datasheet using the conventional terminology BFA7 - BFA0 to denote the 8 address bits
required to designate a byte address within a buffer. Main memory addressing is referenced
using the terminology A17 - A0, where A17 - A8 denotes the 10 address bits required to desig-
nate a page address and A7 - A0 denotes the 8 address bits required to designate a byte
address within a page.
4 AT45DB021D
3638F–DFLASH–4/08
Share Link: 