S25FL004K Meet Spansion Inc., S25FL004K Datasheet - Page 60

• 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.

7.35
60
Read Security Registers (48h)
The Read Security Register instruction is similar to the Fast Read instruction and allows one or more data
bytes to be sequentially read from one of the three security registers. The instruction is initiated by driving the
CS# pin low and then shifting the instruction code “48h” followed by a 24-bit address (A23-A0) and eight
“dummy” clocks into the SI pin. The code and address bits are latched on the rising edge of the CLK pin. After
the address is received, the data byte of the addressed memory location will be shifted out on the SO pin at
the falling edge of CLK with most significant bit (MSB) first. The byte address is automatically incremented to
the next byte address after each byte of data is shifted out. Once the byte address reaches the last byte of the
register (byte FFh), it will reset to 00h, the first byte of the register, and continue to increment. The instruction
is completed by driving CS# high. The Read Security Register instruction sequence is shown in
If a Read Security Register instruction is issued while an Erase, Program or Write cycle is in process
(BUSY=1), the instruction is ignored and will not have any effects on the current cycle. The Read Security
Register instruction allows clock rates from DC to a maximum of F
Characteristics on page
Security Register #1
Security Register #2
Security Register #3
Address
CLK
CLK
CS#
CS#
SO
SO
SI
SI
Mode 3
Mode 0
= MSB
32
7
0
6
33 34 35
64).
Figure 7.39 Read Security Registers Instruction Sequence
1
5
Dummy Byte
Instruction (48h)
S25FL004K / S25FL008K / S25FL016K
2
4
3
3
36
A23-16
00h
00h
00h
4
2
37 38 39 40
1
5
6
0
7
7
D a t a
23 22
8
6
41
9
5
42 43 44
24-bit Address
Data Out 1
21
0 0 0 1 b
0 0 1 0 b
0 0 1 1 b
10
A15-12
4
S h e e t
3
3
28 29
2
45 46
2
1
1
30 31
0
R
0
47
(see
7
6
S25FL004K-016K_00_02 July 14, 2011
Section 8.6, AC Electrical
0 0 0 0 b
0 0 0 0 b
0 0 0 0 b
A11-8
5
Data Out 2
4
3
2
1
0
Byte Address
Byte Address
Byte Address
7
Figure
A7-0
7.39.