I am wondering if ISO 14443A has a packet structure that can be looked at similar to how bluetooth advertisements have a structure of (Length, Type, Data). Eventually I hope to understand how that protocol (ISO 14443A) is used to package the messages used in MiFare Classic. My understanding is that Mifare Classic is "a layer" built on top of the existing ISO 14443A protocol.
Technically there is no ISO 14443A there is ISO 14443 part 1 to 4 and within some part there are two types of modulation Type A or B.
Most cards are compliant up to ISO 14443-2A or ISO 14443-2B at least the majority are compliant up to up to ISO 14443-3A or ISO 14443-3B.
The NFC Wikipedia Page give a nice diagram of the various standards.
The lower levels handle physical, RF (Including Modulation) and Initialization, Anti collision and raw frame data.
ISO 14443-4A and ISO 14443-4B handle a standard protocol (a sort of packet structure).
MiFare Classic cards use up to ISO 14443-3A and then have there own non standard comm structure which can be seen by reading the datasheet for one of the Cards.
Also of the ISO standards can be seen here to help you understand the various standards used.
There is of course on top to this the NDef data standard which is a more packet type structure on how to communicate data across all the NFC Forum standard type Tags (The is also a non standard way for a MiFare Classic to store NDef Data as the MiFare Classic is a non standard propitiatory Nfc Tag)
I hope that helps your understanding.
