256-Mbit J3 (x8/x16)
Appendix A Common Flash Interface
The Common Flash Interface (CFI) specification outlines device and host system software
interrogation handshake which allows specific vendor-specified software algorithms to be used for
entire families of devices. This allows device independent, JEDEC ID-independent, and forward-
and backward-compatible software support for the specified flash device families. It allows flash
vendors to standardize their existing interfaces for long-term compatibility.
This appendix defines the data structure or “database” returned by the Common Flash Interface
(CFI) Query command. System software should parse this structure to gain critical information
such as block size, density, x8/x16, and electrical specifications. Once this information has been
obtained, the software will know which command sets to use to enable flash writes, block erases,
and otherwise control the flash component. The Query command is part of an overall specification
for multiple command set and control interface descriptions called Common Flash Interface, or
CFI.
A.1
Query Structure Output
The Query “database” allows system software to gain information for controlling the flash
component. This section describes the device’s CFI-compliant interface that allows the host system
to access Query data.
Query data are always presented on the lowest-order data outputs (D[7:0]) 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 bytes of the Query structure, “Q” and “R” in ASCII,
appear on the low byte at word addresses 10h and 11h. This CFI-compliant device outputs 00H
data on upper bytes. Thus, the device outputs ASCII “Q” in the low byte (D[7:0]) and 0x00 (00h)
in the high byte (D[15:8]).
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.
52
Datasheet
INTEL [ INTEL ]
