TRF7970A P2P Communication Anti-collision and Data Framing

Hello,

I am working on building an implementation of P2P communication at 106kbps. I'm currently working on the initiator side, but will be doing the passive target side as well.

The application note on P2P communication has been helpful, but I have a few questions:

1. Is the initial RF collision avoidance outlined in Figure 7 achieved by using the test external RF command (0x19) with an RSSI level read, or can it be simply abstracted by using the initial RF collision avoidance command (0x04)?
2. How much of the NFC-A data framing and anti-collision is handled by the TRF7970A? Does the TRF run through the Passive Target SDD or Active Initiator SDD for passive communication automatically, or is that data framing something that needs to be implemented?

I suspect that the general flow for P2P would be as follows (For an active initiator, P2P in passive mode, after soft init and reset completed):

1. Send command 0x04 to TRF7970A- Perform initial RF collision avoidance
2. Write ISO control register 0x08 (receive without CRC) before anti-collision
3. Send command 0x05 to TRF7970A- Response RF Collision Avoidance Command
4. Write ISO control register 0x08 (receive with CRC) after anti-collision completed
5. Reset FIFO Command (0x0F)
6. Transmit with CRC
7. Write DEP packet to the FIFO

Is this correct, or do the SDD packets such as REQ_A, SDD_REQ, etc. and their appropriate responses need to be decoded in the host MCU?

Thanks,

Michael Cerabona