HY29F080 Datasheet, PDF (8/38 Pages) Hynix Semiconductor – 8 Megabit (1M x 8), 5 Volt-only, Flash Memory

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_ID. While in this mode, formerly protected sec-
tors can be programmed or erased by invoking
the appropriate commands (see Device Com-
mands section). Once V_ID is removed from RE-
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_ID
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).
START
APPLY V _CC
Set TRYCNT = 1
Set A9 = OE# = V _ID
Set Address:
A[19:17] = Group to Protect
CE# = V _IL
RESET# = V _IH
WE# = V _IL
8
Wait t_WPP1
WE# = V _IH
A9 = V _ID
A[19:17] = Group to Protect
OE# = CE# = A6 = A0 = V _IL
A1 = V _IH
Read Data
NO
Data = 0x01?
Increment TRYCNT
NO
TRYCNT = 25?
YES
YES
Protect Another
NO
Sector?
YES
DEVICE FAILURE
Figure 1. Sector Group Protect Procedure
Remove V _ID from A9
SECTOR PROTECT
COMPLETE
Rev. 6.1/May 01