256Mb: 3V Embedded Parallel NOR Flash
Block Protection Command Definitions – Address-Data Cycles
Table 17: Block Protection Command Definitions – Address-Data Cycles, 16-Bit (Continued)
Notes 1 and 2 apply to entire table
Address and Data Cycles
1st
2nd
3rd
4th
nth
Command and
Code/Subcode
Bus
Size
A
D
A
D
A
D
A
D
…
A
D
Notes
ENTER VOLATILE
PROTECTION COMMAND
SET (E0h)
x16
555
AA
2AA
55
(BKA)
555
E0
3
PROGRAM VOLATILE
PROTECTION BIT (A0h)
x16
X
A0
(BKA)
BAd
00
READ VOLATILE
PROTECTION BIT STATUS
x16 (BKA) READ(0)
BAd
4, 6,
10
CLEAR VOLATILE
PROTECTION BIT (A0h)
x16
X
A0
(BKA)
BAd
01
55
EXTENDED MEMORY BLOCK Commands
ENTER EXTENDED
MEMORY BLOCK (88h)
x16
x16
x16
x16
555
BAd
X
AA
RD
A0
AA
2AA
555
555
88
90
3
READ EXTENDED
MEMORY BLOCK
PROGRAM EXTENDED
MEMORY BLOCK
BAd
2AA
PD
55
EXIT EXTENDED
555
X
00
MEMORY BLOCK (90/00h)
EXIT PROTECTION Commands
EXIT PROTECTION
x16
X
90
X
00
3
COMMAND SET (90/00h)
1. Key: A = Address and D = Data; X = "Don’t Care;" BAd = any address in the block; BKA =
Bank address; PWDn = password bytes 0 to 7; PWAn = password address, n = 0 to 7;
RD(0) = DQ0 protection indicator bit; If protected, DQ0 = 00h, while if unprotected, DQ0
= 01h. Gray = not applicable. All values in the table are hexadecimal.
Notes:
2. DQ[15:8] are "Don’t Care" during UNLOCK and COMMAND cycles. A[MAX:16] are
"Don’t Care" during UNLOCK and COMMAND cycles, unless an address is required.
3. The ENTER command sequence must be issued prior to any operation. It disables READ
and WRITE operations from and to block 0. READ and WRITE operations from and to
any other block are allowed. Also, when an ENTER COMMAND SET command is issued,
an EXIT PROTECTION COMMAND SET command must be issued to return the device to
READ mode.
4. READ REGISTER/PASSWORD commands have no command code; CE# and OE# are driven
LOW and data is read according to a specified address.
5. Data = Lock register content.
6. All address cycles shown for this command are READ cycles.
7. Only one portion of the password can be programmed by each PROGRAM PASSWORD
command.
8. Each portion of the password can be entered or read in any order as long as the entire
64-bit password is entered or read.
9. For the x16 UNLOCK PASSWORD command, the nth (and final) address cycle equals the
7th address cycle. For the 5th and 6th address cycles, the values for the address and data
PDF: 09005aef84ecabef
m29dw_256g.pdf - Rev. A 10/12 EN
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