The SIC4310 is a dual-interface transponder IC which can be accessed by an NFC/RFID device and UART interface provides
facilities to be connected to various UART devices. In addition, the SIC4310 enables transparent data transmission between
NFC/RFID reader device and UART end device. The RF interface and UART interface behaviour is delineated in this section.
4.1 RF interface
The RF interface of SIC4310 is based on the standard for contactless smart cards ISO 14443A-2. PCD and PICC according to
ISO standard are referred respectively as NFC/RFID device and SIC4310/tag/transponder/chip throughout this document.
The SIC4310 activates itself by energizing RF field generated by its companion NFC/RF device. When the transponder is
powered up and internal supply voltage is higher than the POR threshold, the chip initiates itself and waits silently for an
operational command and then starts transmitting in uplink as a response.
4.1.1 Downlink
In downlink, the RF device starts sending a command to the transponder by interrupting the field. The downlink
communication takes place using 100% ASK modulation with the Miller coding. The transmission bit-rate is 106 kbps (fc/128).