AT25PE80 datasheet(21/61 Pages) RENESAS

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AT25PE80

DS-25PE80-141D–2/2022

Security Features

8.1

Security Register

The device contains a specialized Security Register that can be used for purposes such as unique device serialization or

locked key storage. The register is comprised of a total of 128 bytes (byte locations 0 through 127). All 128 bytes of the

Security Register are factory programmed by Adesto and will contain a unique value for each device. The factory

programmed data is fixed and cannot be changed.

Table 8-1.

Security Register

8.1.1

Reading the Security Register

To read the Security Register, an opcode of 77h and three dummy bytes must be clocked into the device. After the last

dummy bit has been clocked in, the contents of the Security Register can be clocked out on the SO pin. After the last

byte of the Security Register has been read, additional pulses on the SCK pin will result in undefined data being output

on the SO pin.

Deasserting the CS pin will terminate the Read Security Register operation and put the SO pin into a high-impedance

state.

Figure 8-1.

Read Security Register

Security Register Byte Number

· · ·

127

Data Type

Factory Programmed by Adesto

77h

Data

n + 1

Data

n + x

Each transition represents eight bits

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