EN29LV512
USER MODE DEFINITIONS
Standby Mode
The EN29LV512 has a CMOS-compatible standby mode, which reduces the current to
<
1µA
(typical). It is placed in CMOS-compatible standby when the
CE
pin is at V
CC
±
0.3. The device also
has a TTL-compatible standby mode, which reduces the maximum V
CC
current to < 1mA. It is
placed in TTL-compatible standby when the
CE
pin is at V
IH
. When in standby modes, the outputs
are in a high-impedance state independent of the
OE
input.
Read Mode
The device is automatically set to reading array data after device power-up. No commands are required to
retrieve data. The device is also ready to read array data after completing an Embedded Program or
Embedded Erase algorithm.
After the device accepts an Erase Suspend command, the device enters the Erase Suspend mode. The
system can read array data using the standard read timings, except that if it reads at an address within
erase-suspended sectors, the device outputs status data. After completing a programming operation in
the Erase Suspend mode, the system may once again read array data with the same exception. See
“Erase Suspend/Erase 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” additional details.
Output Disable Mode
When the
CE
or
OE
pin is at a logic high level (V
IH
), the output from the EN29LV512 is disabled.
The output pins are placed in a high impedance state.
Auto Select Identification Mode
The autoselect mode provides manufacturer and device identification, and sector protection
verification, through identifier codes output on DQ7–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
ID
(11 V) on address pin A9.
Address pins A8, A6, A1, and A0 must be as shown in Autoselect Codes table. In addition, when
verifying sector protection, the sector 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 DQ7–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
ID
. See “Command Definitions” for details on using the autoselect mode.
Write Mode
Write operations, including programming data and erasing sectors of memory, require the host
system to write a command or command sequence to the device. Write cycles are initiated by
placing the byte or word address on the device’s address inputs while the data to be written is input
on DQ[7:0]. The host system must drive the CE# and WE# pins Low and the OE# pin High for a
valid write operation to take place. All addresses are latched on the falling edge of WE# and CE#,
This Data Sheet may be revised by subsequent versions
or modifications due to changes in technical specifications.
6
©2003 Eon Silicon Solution, Inc., www.essi.com.tw
Rev. B, Issue Date: 2004/01/05
EON [ EON SILICON SOLUTION INC. ]
