HY29F080 Hynix Semiconductor, HY29F080 Datasheet - Page 8

• Manufacturer Part Number: HY29F080
• Description: 8 Megabit (1M X 8), 5 Volt-only, Flash Memory
• Manufacturer: Hynix Semiconductor

HY29F080
The flow chart in Figure 1 illustrates the proce-
dure for protecting sector groups, and timing speci-
fications and waveforms are shown in the specifi-
cations section of this document. Verification of
protection is accomplished as described in the
Electronic ID Mode section and shown in the flow
chart.
The procedure for sector group unprotection is il-
lustrated in the flow chart in Figure 2, and timing
specifications and waveforms are given at the end
of this document. Note that to unprotect any sec-
tor group, all unprotected sector groups must first
be protected prior to the first unprotect write cycle.
Sectors can also be temporarily unprotected as
described in the next section.
Temporary Sector Group Unprotect Operation
This feature allows temporary unprotection of pre-
viously protected sectors to allow changing the
data in-system. Temporary Sector Group Unpro-
tect mode is activated by setting the RESET# pin
to V
tors can be programmed or erased by invoking
8
A[19:17] = Group to Protect
ID
. While in this mode, formerly protected sec-
Set A9 = OE# = V
Set TRYCNT = 1
RESET# = V
Set Address:
APPLY V
W E # = V
CE# = V
START
CC
IL
IL
IH
ID
Figure 1. Sector Group Protect Procedure
A[19:17] = Group to Protect
OE# = CE# = A6 = A0 = V
Protect Another
Data = 0x01?
Read Data
W E # = V
Wait t
A9 = V
A1 = V
Sector?
W P P 1
Y E S
Y E S
ID
IH
IH
IL
N O
N O
the appropriate commands (see Device Com-
mands section). Once V
SET#, all the previously protected sectors are pro-
tected again. Figure 3 illustrates the algorithm.
Electronic ID Mode Operation
The Electronic ID mode provides manufacturer and
device identification and sector group protection
verification through identifier codes output on
DQ[7:0]. This mode is intended primarily for pro-
gramming equipment to automatically match a
device to be programmed with its corresponding
programming algorithm. The Electronic ID infor-
mation can also be obtained by the host through
a command sequence, as described in the De-
vice Commands section.
Operation in the Electronic ID mode requires V
on address pin A[9], with additional requirements
for obtaining specific data items as listed in Table
2:
n
A read cycle at address 0xXXX00 retrieves the
manufacturer code (Hynix = 0xAD).
Increment TRYCNT
DEVICE FAILURE
TRYCNT = 25?
N O
Y E S
ID
is removed from RE-
SECTOR PROTECT
Remove V
C O M P L E T E
ID
Rev. 6.1/May 01
from A9
ID