HY29F002T
START
NOTE: All sectors must be
previously protected.
Increment TRYCNT
Set Sector Address:
A[17:13] = Sector NSEC
A[0] = A[6] = V
APPLY V
IL
CC
A[1] = V IH
Set: TRYCNT = 1
Read Data
NO
Set: NSEC = 0
YES
NO
Data = 0x00?
TRYCNT = 1000?
Set: A[9] = CE# = OE# = V
ID
YES
Set: RESET# = V
IH
YES
WE# = V IL
Wait t WPP2
WE# = V IH
Set:
NSEC = 6?
Remove V
from A[9]
ID
NO
NSEC = NSEC + 1
SECTOR UNPROTECT
COMPLETE
DEVICE FAILURE
A[9] = V
ID
OE# = CE# = V
IL
Figure 2. Sector Unprotect Procedure
DEVICE COMMANDS
START
Device operations are initiated by writing desig-
nated address and data command sequences into
the device. A command sequence is composed
of one, two or three of the following sub-segments:
an unlock cycle, a command cycle and a data
cycle. Table 4 summarizes the composition of the
valid command sequences implemented in the
HY29F002T, and these sequences are fully de-
scribed in Table 5 and in the sections that follow.
RESET# = VID
(All protected sectors
become unprotected)
Perform Program or Erase
Operations
Writing incorrect address and data values or writ-
ing them in the improper sequence resets the
HY29F002T to the Read mode.
RESET# = VIH
(All previously protected
sectors return to
protected state)
Read/Reset 1, 2 Commands
TEMPORARY SECTOR
UNPROTECT COMPLETE
The HY29F002T automatically enters the Read
mode after device power-up, after the RESET#
input is asserted and upon the completion of cer-
tain commands. Read/Reset commands are not
required to retrieve data in these cases.
Figure 3. Temporary Sector Unprotect
Rev. 4.1/May 01
9