The AT88RF1354 is a smart, high performance ISO/IEC 14443 Type B RF Reader IC. The AT88RF1354 communicates with RFID Transponders or Contactless Smartcards using the industry standard ISO/IEC 14443-2 Type B signal modulation scheme and ISO/IEC 14443-3 Type B frame format. Data is exchanged half duplex at a 106k bit per second rate. A two byte CRC_B provides communication error detection capability. The AT88RF1354 is compatible with 3.3 V and 5 V host microcontrollers with two-wire or SPI serial interfaces. In two-wire interface mode the AT88RF1354 operates as a TWI slave and requires four microcontroller pins for data communication and handshaking. In SPI interface mode the AT88RF1354 operates as a mode 0 SPI slave and requires six microcontroller pins for data communication and handshaking. To communicate with an RFID transponder the host microcontroller sends a data packet for transmission over the RF communications channel, and receives the response data packet that is received from the transponder over the RF communications channel. AT88RF1354 performs all RF communication packet formatting, decoding, and communication error checking. The host microcontroller is not burdened with RF encoding, timing, or protocol functions since these tasks are all performed by the AT88RF1354.