128Mb, 256Mb, 512Mb, 1Gb StrataFlash Memory
Common Flash Interface
Common Flash Interface
The common Flash interface (CFI) is part of an overall specification for multiple com-
mand set and control interface descriptions. System software can parse the CFI data-
base structure to obtain information about the device, such as block size, density, bus
width, and electrical specifications. The system software determines which command
set to use to properly perform a WRITE, BLOCK ERASE, or READ command, and to oth-
erwise control the device. Information in the CFI database can be viewed by issuing the
READ CFI command.
READ CFI Structure Output
The READ CFI command obtains CFI database structure information and always out-
puts it on the lower byte, DQ[7:0], for a word-wide (x16) Flash device. This CFI-compli-
ant device always outputs 00h data on the upper byte (DQ[15:8]).
The numerical offset value is the address relative to the maximum bus width that the
device supports, with a starting address of10h, which is a word address for x16 devices.
For example, at a starting address of 10h, a READ CFI command outputs an ASCII Q in
the lower byte and 00h in the higher byte.
In the following tables, address and data are represented in hexadecimal notation. In
addition, because the upper byte of word-wide devices is always 00h, the leading 00 has
been dropped and only the lower byte value is shown.
Table 43: Example of CFI Output (x16 Device) as a Function of Device and Mode
Hex
Offset
Hex
Code
ASCII Value
(DQ[15:8])
ASCII Value
(DQ[7:0])
Device
Address
00010:
00011:
00012:
00013:
00014:
00015:
00016:
00017:
00018:
51
52
00
00
00
00
00
00
00
00
00
Q
R
59
Y
P_IDLO
P_IDHI
PLO
Primary vendor ID
Primary vendor table address
Alternate vendor ID
PHI
A_IDLO
A_IDHI
:
:
:
:
:
:
:
:
Table 44: CFI Database: Addresses and Sections
Address
Section Name
Description
00001:Fh
Reserved
Reserved for vendor-specific information
Command set ID (identification) and vendor data offset
Timing and voltage
00Address010h CFI ID string
0001Bh
00027h
System interface information
Device geometry definition
Layout
PDF: 09005aef8448483a
128_256_512_65nm_g18.pdf - Rev. F 8/11 EN
Micron Technology, Inc. reserves the right to change products or specifications without notice.
81
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