S25FL008K Meet Spansion Inc., S25FL008K Datasheet - Page 50

• Manufacturer Part Number: S25FL008K
• Description: 8-mbit Cmos 3.0 Volt Flash Memory With 104-mhz Spi Serial Peripheral Interface Multi I/o Bus
• Manufacturer: Meet Spansion Inc.

50
6.2.34
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
(02h) on page 34
CLK
CLK
CS#
CS#
Security Register #1
Security Register #2
Security Register #3
SI
SI
Mode 3
Mode 0
Address
= MSB
40
7
for detail descriptions).
6
41 42 43 44 45
0
5
1
Figure 6.40 Program Security Registers Instruction Sequence
Data Byte 2
D a t a
4
Instruction (42h)
2
3
3
A23-16
2
Security Register Lock Bits (LB3, LB2, LB1) on page 14
S h e e t
00h
00h
00h
4
1
46 47 48
5
0
S25FL008K
6
7
7
( A d v a n c e
6
49
23
8
5
50 51 52 53 54 55
22 21
9
Data Byte 3
A15-12
0 0 0 1
0 0 1 0
0 0 1 1
24-bit Address
4
10
3
28 29
2
3
I n f o r m a t i o n )
1
Figure
2
1
0
30 31 32 33 34
6.40. The Security Register Lock Bits
0
0 0 0 0
0 0 0 0
0 0 0 0
7
A11-8
7
S25FL008K_00_01 July 30, 2010
6
6
5
Data Byte 256
Data Byte 1
5
4
4
35 36 37 38 39
3
and
3
2
Byte Address
Byte Address
Byte Address
2
Page Program
1
A7-0
1
0
0
Mode 3
Mode 0