AT88RF04C-MY1G View Datasheet(PDF) - Atmel Corporation

Part Name

Description

Manufacturer

AT88RF04C-MY1G

CryptoRF® Specification

Atmel Corporation 

AT88SC0808/1616/3216/6416CRF, AT88RF04C

6.19. Check Password Command [$cC]

The Check Password command transmits a password for validation.

Reader

PICC

Command >

CID

$C

Password Index

PW 1

PW 2

PW 3

CRC1

CRC2

Echo Command >

CID

$C

ACK/NACK

STATUS

CRC1

CRC2

6.19.1. Operation

To read or write data in User Zones that require a password for access the host must carry out a password validation

operation. To write data to the Configuration Memory during personalization the host must carry out a transport

password validation operation. The host uses the Check Password command to send the password for validation

against the password selected with the Password Index byte. Only PICCs in the Active State are permitted to answer

this command.

If the Check Password is successful, the Password Attempts Counter (PAC) is cleared and the ACK response is

issued. Only one password is active at any time. If the Check Password fails, the PAC is incremented and a NACK

response is issued. The Check Password success or failure is memorized and active until the PICC is powered down,

removed from the Active state, or until a new Check Password is received. If the password trials limit is reached,

subsequent Check Password commands will be rejected.

If the Authentication Communication mode or the Encryption Communication mode is active, then the three PW bytes

are encrypted. In Normal Communication mode the PW bytes are not encrypted.

6.19.2. Command Field Descriptions

CID:

The Card ID assigned by the ATTRIB command.

Password Index: Identifies the password register that the PICC will check the transmitted password against.

63

5276C–RFID–3/09

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