E S I
I
ES
Excel Semiconductor inc.
The device enters the CMOS standby mode when
CE# and RESET# pins are both held at Vcc
+
0.3V.
(Note that this is a more restricted voltage range
than V
IH.
) If CE# and RESET# are held at V
IH
, but
not within Vcc
+
0.3V, the device will be still in the
standby mode, but the standby current will be
greater than the CMOS standby current (0.2uA typi-
cally). When the device is in the standby mode, only
standard access time (t
CE
) is required for read
access, before it is ready for read data. And even if
the device is deselected by CE# pin during erase or
programming operation, the device draws active cur-
rent until the operation is completely done. While the
device stays in the standby mode, the output is
placed in the high impedance state, independent of
the OE# input.
The device can enter the deep power-down mode
where current consumption is greatly reduced down
to less than 0.2uA typically by the following three
ways:
-
CMOS standby
( CE#, RESET# = Vcc + 0.3V )
-
During the device reset
( RESET# = Vss
+ 0.3V )
-
In Autosleep Mode
( after t
ACC
+ 30ns )
set-up cycle and the last cycle with the program data
and addresses. In this mode, two unlock cycles are
saved ( or bypassed ).
Sector Addresses
The entire memory space of cell array is divided into
a many of small sectors: 16Kbytes x 1, 8Kbytes x 2,
32Kbytes x 1 and 64Kbytes x 7 main sectors. In
erase operation, a single sector, multiple sectors, or
the entire device (chip erase) can be selected for
erase. The address space that each sector occupies
is shown in detail in the Table 3-4.
Autoselect Mode
Flash memories are intended for use in applications
where the local CPU alters memory contents. In
such applications, manufacturer and device identifi-
cation (ID) codes must be accessible while the
device resides in the target system ( the so called
“in-system program”). On the other hand, signature
codes have been typically accessed by raising A9
pin to a high voltage in PROM programmers. How-
ever, multiplexing high voltage onto address lines is
not the generally desired system design practice.
Therefore, in the ES29LV400 device an
autoselect
command
is provided to allow the system to access
the signature codes without any high voltage. The
conventional
A9 high-voltage method
used in the
PROM programers for signature codes are still sup-
ported in this device.
If the system writes the autoselect command
sequence, the device enters the Autoselect mode.
The system can then read some useful codes such
as manufacturer and device ID from the internal reg-
isters on DQ7 - DQ0. Standard read cycle timings
apply in this mode. In the Autoselect mode, the fol-
lowing three informations can be accessed through
either autoselect command method or A9 high-volt-
age autoselect method. Refer to the Table 2.
-
Manufacturer ID
-
Device ID
-
Sector protection verify
Refer to the CMOS DC characteristics Table 7 for
further current specification.
Autosleep Mode
The device automatically enters a deep power-down
mode called the autosleep mode when addresses
remain stable for t
ACC
+30ns. In this mode, current
consumption is greatly reduced ( less than 0.2uA
typical ), regardless of CE#, WE# and OE# control
signals.
Writing Commands
To write a command or command sequences to ini-
tiate some operations such as program or erase, the
system must drive WE# and CE# to V
IL
, and OE# to
V
IH
. For program operations, the BYTE# pin deter-
mines whether the device accepts program data in
bytes or words. Refer to “BYTE# timings for Write
Operations” in the Fig. 19 for more information.
Hardware Device Reset ( RESET# )
The RESET# pin provides a hardware method of
resetting the device to read array data. When the
RESET# pin is driven low for at least a period of t
RP
,
Unlock Bypass Mode
To reduce more the programming time, an unlock-
bypass mode is provided. Once the device enters
this mode, only two write cycles are required to ini-
tiate the programming operation instead of four
cycles in the normal program command sequences
which are composed of two unlock cycles, program
ES29LV400E
7
Rev.0B January 5, 2006
EXCELSEMI [ EXCEL SEMICONDUCTOR INC. ]
