DATA SHEET
tire chip, or suspending/resuming the erase operation.
After the system writes the autoselect command se-
quence, the device enters the autoselect mode. The
system can then read autoselect codes from the inter-
nal register (which is separate from the memory array)
on DQ7–DQ0. Standard read cycle timings apply in this
mode. Refer to the “Autoselect Mode” and “Autoselect
I
CC2
in the DC Characteristics table represents the ac-
tive current specification for the write mode. The “AC
Characteristics” section contains timing specification
tables and timing diagrams for write operations.
In the DC Characteristics tables, I
CC3
represents the
standby current specification.
RESET#: Hardware Reset Pin
The RESET# pin provides a hardware method of reset-
ting the device to reading array data. When the system
drives the RESET# pin low for at least a period of t
RP
,
the device
immediately terminates
any operation in
progress, tristates all data output pins, and ignores all
read/write attempts for the duration of the RESET#
pulse. The device also resets the internal state ma-
chine to reading array data. The operation that was in-
terrupted 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 V
IL
, the device enters
the TTL standby mode; if RESET# is held at V
SS
±
0.5 V, the device enters the CMOS standby mode.
The RESET# pin may be tied to the system reset cir-
cuitry. 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 oper-
ation, the RY/BY# pin remains a “0” (busy) until the in-
ternal reset operation is complete, which requires a
time of t
READY
(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 t
READY
(not during Embedded Algo-
rithms). The system can read data t
RH
after the RE-
SET# pin returns to V
IH
.
Refer to the AC Characteristics tables for RESET# pa-
rameters and timing diagram.
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
teristics section for timing diagrams.
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, inde-
pendent of the OE# input.
The device enters the CMOS standby mode when CE#
and RESET# pins are both held at V
CC
±
0.5 V. (Note
that this is a more restricted voltage range than V
IH
.)
The device enters the TTL standby mode when CE#
and RESET# pins are both held at V
IH
. The device re-
quires standard access time (t
CE
) for read access when
the device is in either of these standby modes, before it
is ready to read data.
The device also enters the standby mode when the RE-
SET# pin is driven low. Refer to the next section, “RE-
If the device is deselected during erasure or program-
ming, the device draws active current until the
operation is completed.
Output Disable Mode
When the OE# input is at V
IH
, output from the device is
disabled. The output pins are placed in the high imped-
ance state.
10
Am29F800B
21504E5 November 2, 2006
AMD [ ADVANCED MICRO DEVICES ]
