DS2775K Maxim Integrated, DS2775K Datasheet - Page 10
DS2775K
Manufacturer Part Number
DS2775K
Description
Power Management IC Development Tools
Manufacturer
Maxim Integrated
Series
DS2775, DS2776, DS2777, DS2778r
Datasheet
1.DS2777K.pdf
(17 pages)
DS2775–DS2778 Evaluation Kits
Figure 18. SHA-1 Tab
Figure 19. The Secret
Figure 20. The ROM ID
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The DS2776/DS2778 use an 8-byte Secret, the 8-byte
ROM ID code of the device, and an 8-byte Challenge
to generate a 20-byte Message Digest (also called the
MAC) using the SHA-1 encryption algorithm. See
Figure 18. The DS2775/DS2777 do not support the
SHA-1 functions.
The user can clear the 8 bytes of the secret by left-
clicking on the Clear Secret button. The top-right text
box is the LSB of the secret, and the bottom-left text
box is the MSB of the secret. (All text boxes are dis-
played in this same format.) See Figure 19.
The user can also permanently lock the secret by left-
clicking on the Lock Secret button. Once the secret is
locked, it cannot be changed and cannot be read from
the DS2776/DS2778. The software prompts the user to
make sure the secret is ready to be permanently locked.