S25FL004K Meet Spansion Inc., S25FL004K Datasheet - Page 54

• 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.

7.30
54
Read Unique ID Number (4Bh)
The Read Unique ID Number instruction accesses a factory-set read-only 64-bit number that is unique to
each S25FL004K/S25FL008K/S25FL016K device. The ID number can be used in conjunction with user
software methods to help prevent copying or cloning of a system. The Read Unique ID instruction is initiated
by driving the CS# pin low and shifting the instruction code “4Bh” followed by a four bytes of dummy clocks.
After which, the 64-bit ID is shifted out on the falling edge of CLK as shown in
CLK
CLK
CS#
CS#
SO
SO
SI
SI
= MSB
Mode 3
Mode 0
24 25 26 27 28
0
1
Dummy 3
Figure 7.34 Read Unique ID Number Instruction Sequence
Instruction (4B)
2
S25FL004K / S25FL008K / S25FL016K
3
29 30 31
4
5
6
32 33
7
High Impedance
D a t a
8
34
Dummy 4
9
Dummy 1
35 36 37 38 39
S h e e t
10 11
12 13
14 15 16
* *
40
63
S25FL004K-016K_00_02 July 14, 2011
64-bit Unique Serial Number
41 42
62 61 60 59
Figure
17 18 19
43 44 101 102 103
Dummy 2
7.34.
2
20 21 22 23
1
0
Mode 3
Mode 0