S25FL004K Meet Spansion Inc., S25FL004K Datasheet - Page 59

• Manufacturer Part Number: S25FL004K
• Description: 4-mbit / 8-mbit / 16-mbit Cmos 3.0 Volt Flash Memory With 104-mhz Spi Serial Peripheral Interface Multi I/o Bus
• Manufacturer: Meet Spansion Inc.

7.34
July 14, 2011 S25FL004K-016K_00_02
Program Security Registers (42h)
The Program Security Register instruction is similar to the Page Program instruction. It allows from one byte
to 256 bytes of security register data to be programmed at previously erased (FFh) memory locations. A Write
Enable instruction must be executed before the device will accept the Program Security Register Instruction
(Status Register bit WEL= 1). The instruction is initiated by driving the CS# pin low then shifting the instruction
code “42h” followed by a 24-bit address (A23-A0) and at least one data byte, into the SI pin. The CS# pin
must be held low for the entire length of the instruction while data is being sent to the device.
The Program Security Register instruction sequence is shown in
(LB3:1) in the Status Register-2 can be used to OTP protect the security registers. Once a lock bit is set to 1,
the corresponding security register will be permanently locked, and a Program Security Register instruction to
that register will be ignored (see Security Register Lock Bits (LB3, LB2, LB1)
(02h)
CLK
CLK
CS#
CS#
Security Register #1
Security Register #2
Security Register #3
SI
SI
on page 41
Mode 3
Mode 0
Address
= MSB
7
40
for detail descriptions).
6
41 42 43 44 45
0
5
Figure 7.38 Program Security Registers Instruction Sequence
1
Data Byte 2
D a t a
4
Instruction (42h)
2
S25FL004K / S25FL008K / S25FL016K
3
3
A23-16
2
00h
00h
00h
4
S h e e t
1
46 47 48
5
0
6
7
7
6
49
23
8
5
50 51 52 53 54 55
22 21
9
0 0 0 1 b
0 0 1 0 b
0 0 1 1 b
Data Byte 3
A15-12
24-bit Address
4
10
3
2
28 29
3
1
Figure
2
1
0
30 31 32 33 34
7.38. The Security Register Lock Bits
0
0 0 0 0 b
0 0 0 0 b
0 0 0 0 b
7
A11-8
7
on page 17
6
6
5
Data Byte 256
Data Byte 1
5
4
4
35 36 37 38 39
3
and Page Program
3
2
Byte Address
Byte Address
Byte Address
2
1
A7-0
1
0
0
Mode 3
Mode 0
59