P30
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 9.2, “Device Commands” on page 45). 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 35: Summary of Query Structure Output as a Function of Device and Mode
Hex
Hex
Code
51
52
59
ASCII
Value
"Q"
"R"
"Y"
Device
Offset
00010:
00011:
00012:
Device Addresses
November 2007
Order Number: 306666-11
Datasheet
87
NUMONYX [ NUMONYX B.V ]
