E
2-MBIT SmartVoltage BOOT BLOCK FAMILY
3.2.2
INTELLIGENT IDENTIFIERS
3.3
Write Operations
To read the manufacturer and device codes, the
device must be in intelligent identifier read mode,
which can be reached using two methods: by
writing the Intelligent Identifier command (90H) or
by taking the A9 pin to VID. Once in intelligent
identifier read mode, A0 = 0 outputs the manu-
facturer’s identification code and A0 = 1 outputs the
device code. In byte-wide mode, only the lower byte
of the above signatures is read (DQ15/A–1 is a
“don’t care” in this mode). See Table 5 for product
signatures. To return to read array mode, write a
Read Array command (FFH).
3.3.1
COMMAND USER INTERFACE (CUI)
The Command User Interface (CUI) is the interface
between the microprocessor and the internal chip
controller. Commands are written to the CUI using
standard microprocessor write timings. The
available commands are Read Array, Read
Intelligent Identifier, Read Status Register, Clear
Status Register, Erase and Program (summarized
in Tables 6 and 7). The three read modes are read
array, intelligent identifier read, and status register
read. For Program or Erase commands, the CUI
informs the Write State Machine (WSM) that a
program or erase has been requested. During the
execution of a Program command, the WSM will
control the programming sequences and the CUI
will only respond to status reads. During an erase
cycle, the CUI will respond to status reads and
erase suspend. After the WSM has completed its
task, it will set the WSM Status bit to a “1” (ready),
which indicates that the CUI can respond to its full
command set. Note that after the WSM has
returned control to the CUI, the CUI will stay in the
current command state until it receives another
command.
Table 5. Intelligent Identifier Table
Product
Mfr. ID
Device ID
-T
-B
(Top Boot) (Bottom Boot)
28F200
28F002
0089 H
89 H
2274 H
7C H
2275 H
7D H
3.3.1.1
Command Function Description
Device operations are selected by writing specific
commands into the CUI. Tables 6 and 7 define the
available commands.
17
SEE NEW DESIGN RECOMMENDATIONS
INTEL [ INTEL ]
