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programming operation in the Sector Erase Suspend mode, the system may once again read array
data with the same exception. See “Sector Erase Suspend/Resume Commands” for more additional
information.
The system must issue the reset command to re-enable the device for reading array data if DQ5 goes
high or while in the autoselect mode. See the “Reset Command” for additional details.
Output Disable Mode
When the OE# pin is at a logic high level (V
B
IH
are placed in a high impedance state.
Standby Mode
The device has a CMOS-compatible standby mode, which reduces the
placed in CMOS-compatible standby when the CE# pin is at V
B
CC
also be at CMOS input levels. The device also has a TTL-compatible standby mode, which reduces the
maximum V
B
CC
When in standby modes, the outputs are in a high-impedance state independent of the OE# input.
Automatic Sleep Mode
The device has an automatic sleep mode, which minimizes power consumption. The devices will enter
this mode automatically when the states of address bus remain stable for t
acc
+ 30ns. ICC
4
in the DC
Characteristics table shows the current specification. With standard access times, the device will output
new data when addresses change.
Writing Command Sequences
To write a command or command sequence to program data to the device or erase data, the system
has to drive WE# and CE# to V
B
IL
, and OE# to V
B
IH
The device has an
Unlock Bypass
mode to facilitate faster programming. Once the device enters the
Unlock Bypass mode, only two write cycles are required to program a word, instead of four.
The system can also read the autoselect codes by entering the autoselect mode, which need the
autoselect command sequence to be written. Please refer to the “Command Definitions” for all the
available commands.
Autoselect Identification Mode
The autoselect mode provides manufacturer and device identification, and sector protection verification,
through identifier codes output on DQ15–DQ0. This mode is primarily intended for programming
equipment to automatically match a device to be programmed with its corresponding programming
algorithm. However, the autoselect codes can also be accessed in-system through the command
register.
When using programming equipment, the autoselect mode requires V
B
ID
pin A9. Address pins A6, A1, and A0 must be as shown in Autoselect Codes table. In addition, when
verifying sector group protection, the sector group address must appear on the appropriate highest
order address bits. Refer to the corresponding Sector Address Tables. The “Command Definitions”
table shows the remaining address bits that are don’t-care. When all necessary bits have been set as
required, the programming equipment may then read the corresponding identifier code on DQ15–DQ0.
To access the autoselect codes in-system; the host system can issue the autoselect command via the
command register, as shown in the Command Definitions table. This method does not require V
B
ID
This Data Sheet may be revised by subsequent versions 2005 Eon Silicon Solution, Inc., www.essi.com.tw
or modifications due to changes in technical specifications.
Rev. C, Issue Date: 2007/01/23
EN29LV640
B
), the output from the device is disabled. The output pins
B
current to
<
1μA (typical). It is
B
±
0.5. RESET# and BYTE# pin must
B
current to < 1mA. It is placed in TTL-compatible standby when the CE# pin is at V
B
IH
B
.
B
.
B
(10.5 V to 11.5 V) on address
B
. See