A d v a n c e I n f o r m a t i o n
Refer to the DC Characteristics table for the active current specification for the
write mode. The AC Characteristics section contains timing specification tables
and timing diagrams for write operations.
Write Buffer
Write Buffer Programming allows the system write to a maximum of 16 words/32
bytes in one programming operation. This results in faster effective programming
time than the standard programming algorithms. See “Write Buffer” for more
information.
Accelerated Program Operation
The device offers accelerated program operations through the ACC function. This
is one of two functions provided by the WP#/ACC pin. This function is primarily
intended to allow faster manufacturing throughput at the factory.
If the system asserts VHH on this pin, the device automatically enters the afore-
mentioned Unlock Bypass mode, temporarily unprotects any protected sector
groups, and uses the higher voltage on the pin to reduce the time required for
program operations. The system would use a two-cycle program command se-
quence as required by the Unlock Bypass mode. Removing VHH from the WP#/
ACC pin returns the device to normal operation. Note that the WP#/ACC pin must
not be at VHH for operations other than accelerated programming, or device dam-
age may result. WP# has an internal pullup; when unconnected, WP# is at VIH
.
Autoselect Functions
If the system writes the autoselect command sequence, the device enters the au-
toselect 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” section on page
44 and “Autoselect Command Sequence” section on page 58 sections for more
information.
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.
The device enters the CMOS standby mode when the CE# and RESET# pins are
both held at VIO ± 0.3 V. (Note that this is a more restricted voltage range than
VIH.) If CE# and RESET# are held at VIH, but not within VIO ± 0.3 V, the device
will be in the standby mode, but the standby current will be greater. The device
requires standard access time (tCE) for read access when the device is in either
of these standby modes, before it is ready to read data.
If the device is deselected during erasure or programming, the device draws ac-
tive current until the operation is completed.
Refer to the “DC Characteristics” section on page 86 for the standby current
specification.
Automatic Sleep Mode
The automatic sleep mode minimizes Flash device energy consumption. The de-
vice automatically enables this mode when addresses remain stable for tACC
+
30 ns. The automatic sleep mode is independent of the CE#, WE#, and OE# con-
May 13, 2004 27631A4
S29GLxxxN MirrorBitTM Flash Family
17
SPANSION [ SPANSION ]
