W25Q16BV
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11.2.30
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 W25Q16BV 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 figure 29.
24 25
26
27 28
29 30
31 32 33
34 35 36 37 38
39
40
41 42 43 44 101 102 103
DO
63 62 61 60 59
2
1
0
*
*=MSB
DO
24 25
26
27 28
29 30
31 32 33
34 35 36 37 38
39
40
41 42 43 44 101 102 103
DO
63 62 61 60 59
2
1
0
*
*=MSB
DO
Figure 29. Read Unique ID Number Instruction Sequence Diagram
