Standardisation - RFID: Fundamentals and Applications in Contactless Smart Cards and Identification - page 239

Contact
operation

Power Off

Vcc = ON

No Contactless?

Yes

any command

HALT state IDLE state

REQA

Wake-Up

SELECT (NVB < 40)

HALT | Error READY state

SELECT (NVB = 40)

Selected

HALT | Error

HALT | Error

Active state

Exchange APDUs

ISO 14443-4

Figure 9.16 State diagram of a Type A smart card in accordance with ISO 14443 (Berger,
1998)

S 0110 010 E

LSB MSB

Figure 9.17 The reader's Request command for Type A cards (REQA) is made up of only
7 data bits. This reliably rules out the misinterpretation of useful data destined for another card
as a REQUEST command (S = start of frame, E = end of frame)