May 7, 2004 S29PL127H_129H_00A1
S29PL127H/S29PL129H
13
Pre l i m i n a r y
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.
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 +
150 ns. The automatic sleep mode is independent of the CE#, WE#, and OE#
control signals. Standard address access timings provide new data when ad-
dresses are changed. While in sleep mode, output data is latched and always
available to the system. Note that during automatic sleep mode, OE# must be at
VIH before the device reduces current to the stated sleep mode specification. ICC5 specification.
RESET#: Hardware Reset Pin
The RESET# pin provides a hardware method of resetting the device to reading
array data. When the RESET# pin is driven low for at least a period of tRP, the
device immediately terminates any operation in progress, tristates all output
pins, and ignores all read/write commands for the duration of the RESET# pulse.
The device also resets the internal state machine to reading array data. The op-
eration that was interrupted should be reinitiated once the device is ready to
accept another command sequence, to ensure data integrity.
Current is reduced for the duration of the RESET# pulse. When RESET# is held
at VSS±0.3 V, the device draws CMOS standby current (ICC4). If RESET# is held at VIL but not within VSS±0.3 V, the standby current will be greater.
The RESET# pin may be tied to the system reset circuitry. A system reset would
thus also reset the Flash memory, enabling the system to read the boot-up firm-
ware from the Flash memory.
If RESET# is asserted during a program or erase operation, the RY/BY# pin re-
mains a “0” (busy) until the internal reset operation is complete, which requires
a time of tREADY (during Embedded Algorithms). The system can thus monitor RY/
BY# to determine whether the reset operation is complete. If RESET# is asserted
when a program or erase operation is not executing (RY/BY# pin is “1”), the reset
operation is completed within a time of tREADY (not during Embedded Algorithms).
The system can read data tRH after the RESET# pin returns to VIH.
for the timing diagram.