HY29F800A Hynix Semiconductor, HY29F800A Datasheet - Page 8

• Manufacturer Part Number: HY29F800A
• Description: Flash Memory
• Manufacturer: Hynix Semiconductor

HY29F800A
the duration of the RESET# pulse. The device also
resets the internal state machine to reading array
data. If an operation was interrupted by the as-
sertion of RESET#, it 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 as described in the Standby Operation sec-
tion above.
If RESET# is asserted during a program or erase
operation, the RY/BY# pin remains Low (busy) until
the internal reset operation is complete, which re-
quires a time of t
rithms). The system can thus monitor RY/BY# to
determine when the reset operation completes,
and can perform a read or write operation t
RY/BY# goes High. If RESET# is asserted when
a program or erase operation is not executing (RY/
BY# pin is High), the reset operation is completed
within a time of t
form a read or write operation t
SET# pin returns High .
The RESET# pin may be tied to the system reset
signal. Thus, a system reset would also reset the
8
A[18:12] = Sector to Protect
Set A9 = OE# = V
Set TRYCNT = 1
R E S E T # = V
Set Address:
A P P L Y V
W E # = V
CE# = V
START
CC
IL
IL
IH
RP
ID
. In this case, the host can per-
READY
(during Automatic Algo-
Figure 1. Sector Protect Procedure
RH
A[18:12] = Sector to Protect
OE# = CE# = A6 = A0 = V
after the RE-
Protect Another
Data = 0x01?
Read Data
W E # = V
Wait t
A9 = V
A1 = V
Sector?
RB
W P P 1
Y E S
Y E S
ID
IH
after
IH
IL
N O
N O
device, enabling the system to read the boot-up
firmware from the Flash memory.
Sector Protect/Unprotect Operations
Hardware sector protection can be invoked to dis-
able program and erase operations in any single
sector or combination of sectors. This function is
typically used to protect data in the device from
unauthorized or accidental attempts to program
or erase the device while it is in the system (e.g.,
by a virus) and is implemented using programming
equipment. Sector unprotection re-enables the
program and erase operations in previously pro-
tected sectors.
Table 1 identifies the nineteen sectors and the
address range that each covers. The device is
shipped with all sectors unprotected.
The sector protect/unprotect operations require a
high voltage (V
and/or OE# control pins, as detailed in Table 3.
When implementing these operations, note that
V
V
ing V
CC
ID
, and that V
must be applied to the device before applying
CC
Increment TRYCNT
DEVICE FAILURE
from the device.
T R Y C N T = 2 5 ?
ID
N O
Y E S
ID
should be removed before remov-
) on address pin A[9] and the CE#
SECTOR PROTECT
R e m o v e V
C O M P L E T E
ID
Rev. 1.1/Feb 02
from A9