D a t a
S h e e t
The internal state machine is set for reading array data upon device power-up,
or after a hardware reset. This ensures that no spurious alteration of the memory
content occurs during the power transition. No command is necessary in this
mode to obtain array data. Standard microprocessor read cycles that assert valid
addresses on the device address inputs produce valid data on the device data
outputs. The device remains enabled for read access until the command register
contents are altered.
See
Reading Array Data, on page 19
for more information. Refer to the AC table
for timing specifications and to
for the timing diagram. I
CC1
in the DC Characteristics table represents the active current specification for
reading array data.
Writing Commands/Command Sequences
To write a command or command sequence (which includes programming data
to the device and erasing sectors of memory), the system must drive WE# and
CE# to V
IL
, and OE# to V
IH
.
For program operations, the BYTE# pin determines whether the device accepts
program data in bytes or words. Refer to
Word/Byte Configuration, on page 11
for more information.
The device features an
Unlock Bypass
mode to facilitate faster programming.
Once the device enters the Unlock Bypass mode, only two write cycles are re-
quired to program a word or byte, instead of four. The
Word/Byte Program
Command Sequence, on page 20
contains details on programming data to the
An erase operation can erase one sector, multiple sectors, or the entire device.
Table 2, on page 14
and
Table 3, on page 15
indicate the address space that each
select a sector. The
Command Definitions, on page 19
contains details on erasing
a sector or the entire chip, or suspending/resuming the erase operation.
After the system writes the autoselect command sequence, the device enters the
autoselect mode. The system can then read autoselect codes from the internal
register (which is separate from the memory array) on DQ7–DQ0. Standard read
cycle timings apply in this mode. Refer to the
Autoselect Mode, on page 15
and
Autoselect Command Sequence, on page 20
for more information.
CC2
the write mode. The
AC Characteristics, on page 38
contains timing specification
tables and timing diagrams for write operations.
Program and Erase Operation Status
During an erase or program operation, the system may check the status of the
operation by reading the status bits on DQ7–DQ0. Standard read cycle timings
and I
CC
read specifications apply. Refer to
Write Operation Status, on page 27
for more information, and to
AC Characteristics, on page 38
Standby Mode
When the system is not reading or writing to the device, it can place the device
in the standby mode. In this mode, current consumption is greatly reduced, and
the outputs are placed in the high impedance state, independent of the OE#
input.
12
S29AL008D
S29AL008D_00A3 June 16, 2005
SPANSION [ SPANSION ]
