Hi @tduong
Please see below two pictures. two implementation of card emulation.
scenario 1: card emulation by DH_NFCEE, pn7160 is responsible for forwarding the communication from the external Reader/Writer to DH-NFCEE.

scenario 2: Card Emulation over NFCC, the card is emulated on the NFCC

To switch between scenario 1 and scenario 2, we use this flag NXP_T4T_NFCEE_ENABLE
If we want to use scenario 1 (card emulation by the DH-NFCEE): NXP_T4T_NFCEE_ENABLE = 0x00.
If we want to use scenario 2 (card emulation over NFCC): NXP_T4T_NFCEE_ENABLE = 0x01.
Regards
Daniel