Nanjing Zhongke Microelectronics Si512

Si512 is a highly integrated NFC front- end for contactless communication at 13.56 MHz. This NFC front- end utilizes an outstanding modulation and demodulation concept completely integrated for different kinds of contactless communication methods and protocols at 13.56 MHz and supports automatic carrier detection function. The Si512 NFC front- end supports 5 different operating modes:

• Reader/Writer mode supporting ISO/IEC 14443A and FeliCa scheme
• Reader/Writer mode supporting ISO/IEC 14443B
• Card Operation mode supporting ISO/IEC 14443A and FeliCa scheme
• NFCIP-1 mode
• ACD mode, automatic RF card and RF field detection with extremely low power consumption at 13.56 MHz

The Si512's internal transmitter part is able to drive a reader/writer antenna designed to communicate with ISO/IEC 14443A cards and transponders without additional active circuitry. The receiver part provides a robust and efficient implementation of a demodulation and decoding circuitry for signals from ISO/IEC 14443A compatible cards and transponders. The digital part handles the complete ISO/IEC 14443A framing and error detection (Parity and CRC).

The Si512 supports all layers of the ISO/IEC 14443B reader/writer communication scheme, given correct implementation of additional components, like oscillator, power supply, coil etc. and provided that standardized protocols, e.g. like ISO/IEC 14443- 4 and/or ISO/IEC 14443B anticollision are correctly implemented.

Enabled in Reader/Writer mode for FeliCa, the Si512 NFC front- end supports the FeliCa communication scheme. The receiver part provides a robust and efficient implementation of the demodulation and decoding circuitry for FeliCa coded signals. The digital part handles the FeliCa framing and error detection like CRC. The Si512 supports contactless communication using FeliCa Higher transfer speeds up to 424 kbit/s in both directions.

In Card Operation mode, the Si512 NFC front- end is able to answer to a reader/writer command either according to the FeliCa or ISO/IEC 14443A card interface scheme without additional active circuitry. The Si512 generates the digital load modulated signals and in addition with an external circuit the answer can be sent back to the reader/writer.

Si512 NFC front- end offers the possibility to communicate directly to an NFCIP- 1 device in the NFCIP- 1 mode. The NFCIP- 1 mode offers different communication mode and transfer speeds up to 424 kbit/s according to the Ecma 340 and ISO/IEC 18092 NFCIP- 1 Standard. The digital part handles the complete NFCIP- 1 framing and error detection.

In ACD mode, the chip is mostly in a dormant state and wakes up by 3K RC at a fixed time. It detects a 13.56MHz RF field and RF card with extremely low power consumption, and automatically generates interrupts to wake up the MCU when the field or card is detected. The functions of the detection field and card can be enabled separately. Under a typical 500ms polling cycle, the current is approximately 7.8uA. The entire ACD process does not require MCU intervention.

Various host controller interfaces are implemented:

• SPI interface
• serial UART (similar to RS232 with voltage levels according to pad voltage supply)
• I2C interface
• 8-bit parallel interface