28F640L30, 28F128L30, 28F256L30
Appendix C Common Flash Interface
The Common Flash Interface (CFI) is part of an overall specification for multiple command-set
and control-interface descriptions. This appendix describes the database structure containing the
data returned by a read operation after issuing the CFI Query command (see Section 3.2, “Device
Commands” on page 18). System software can parse this database structure to obtain information
about the flash device, such as block size, density, bus width, and electrical specifications. The
system software will then know which command set(s) to use to properly perform flash writes,
block erases, reads and otherwise control the flash device.
C.1
Query Structure Output
The Query database allows system software to obtain information for controlling the flash device.
This section describes the device’s CFI-compliant interface that allows access to Query data.
Query data are presented on the lowest-order data outputs (DQ7-0) only. The numerical offset value
is the address relative to the maximum bus width supported by the device. On this family of
devices, the Query table device starting address is a 10h, which is a word address for x16 devices.
For a word-wide (x16) device, the first two Query-structure bytes, ASCII “Q” and “R,” appear on
the low byte at word addresses 10h and 11h. This CFI-compliant device outputs 00h data on upper
bytes. The device outputs ASCII “Q” in the low byte (DQ7-0) and 00h in the high byte (DQ15-8).
At Query addresses containing two or more bytes of information, the least significant data byte is
presented at the lower address, and the most significant data byte is presented at the higher address.
In all of the following tables, addresses and data are represented in hexadecimal notation, so the
“h” suffix has been dropped. In addition, since the upper byte of word-wide devices is always
“00h,” the leading “00” has been dropped from the table notation and only the lower byte value is
shown. Any x16 device outputs can be assumed to have 00h on the upper byte in this mode.
Table 18. Summary of Query Structure Output as a Function of Device and Mode
Hex
Hex
ASCII
Device
Offset Code Value
00010:
00011:
00012:
51
52
59
"Q"
"R"
"Y"
Device Addresses
Datasheet
83
INTEL [ INTEL ]
