n25q256 Numonyx, n25q256 Datasheet - Page 99

• Manufacturer Part Number: n25q256
• Description: 256-mbit 3 V, Multiple I/o, 4-kbyte Subsector Erase, Xip Enabled, Serial Flash Memory With 108 Mhz Spi Bus Interface
• Manufacturer: Numonyx

N25Q256 - 3 V
9.1.31
Table 22.
1. Values of (b1, b0) after power-up are defined in
b7-b2
Bit
b1
b0
DQ0
DQ1
Sector Lock
Write Lock
Bit name
C
S
Sector
Down
Read Lock Register (RDLR)
The device is first selected by driving Chip Select (S) Low. The instruction code for the Read
Lock Register (RDLR) instruction is followed by a 3-byte address (A23-A0) pointing to any
location inside the concerned sector. Each address bit is latched-in during the rising edge of
Serial Clock (C). Then the value of the Lock Register is shifted out on Serial Data output
(DQ1), each bit being shifted out, at a maximum frequency fC, during the falling edge of
Serial Clock (C).
The Read Lock Register (RDLR) instruction is terminated by driving Chip Select (S) High at
any time during data output.
Any Read Lock Register (RDLR) instruction, while an Erase, Program or Write cycle is in
progress, is rejected without having any effects on the cycle that is in progress.
If 4-byte address mode is enabled, the device uses a 32-bit address as explained and
shown in
Figure 47. Read Lock Register instruction and data-out sequence
Lock Register out
0
Value
Section 5.1.2: 4 Byte Address Mode on page 25
‘1’
‘0’
‘1’
‘0’
1
High Impedance
2
Instruction
The Write Lock and Lock Down bits cannot be changed. Once a ‘1’ is written to the
Lock Down bit it cannot be cleared to ‘0’, except by a power-up.
The Write Lock and Lock Down bits can be changed by writing new values to them.
Write, Program and Erase operations in this sector will not be executed. The
memory contents will not be changed.
Write, Program and Erase operations in this sector are executed and will modify the
sector contents.
3
(1)
4
5
6
7
MSB
Section 7: Protection
23
8
22 21
9 10
24-bit Address
Reserved
Micron Technology, Inc., reserves the right to change products or specifications without notice.
3
28 29 30 31 32 33 34 35
2
modes.
1
Function
0
MSB
7
6
Lock Register Out
5
4
3
36 37 38
©2010 Micron Technology, Inc. All rights reserved.
2
1
0
39
Instructions
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