256Mb and 512Mb (256Mb/256Mb), P30-65nm
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 Flash device, such as block size, density,
bus width, and electrical specifications. The system software determines which com-
mand set to use to properly perform a Flash WRITE command, a block ERASE or READ
command, and to otherwise control the flash 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 the Flash
device supports. For this Flash device family, the starting address is a 10h, which is a
word address for x16 devices. For example, at this starting address of 10h, a READ CFI
command outputs an ASCII Q in the lower byte and 00h in the higher byte as shown
here.
In all the CFI tables shown here, address and data are represented in hexadecimal nota-
tion. In addition, since the upper byte of word-wide devices is always 00h as shown in
the example here, the leading 00 has been dropped and only the lower byte value is
shown. Following is a table showing the CFI output for a x16 device, beginning at ad-
dress 10h and a table showing an overview of the CFI database sections with their ad-
dresses.
Table 22: 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
:
:
:
:
:
:
:
:
PDF: 09005aef84566799
p30_65nm_256Mb-512mb.pdf - Rev. A 1/13 EN
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