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The board on which the chip is mounted also includes a 16 MB Flash memory chip for storing SDIO driver code, and a 2 Kbit Serial EEPROM for holding parameters such as UART baud rate, according to Arasan. Serial port data rates up to 1 Mbit are supported.


SDIO in a Box Block Diagram
A "virtual serial driver" manages the SDIO protocol transparently, so that applications simply communicate with an RS-233 serial port, according to Arasan. The Windows CE virtual driver is supplied by Bsquare, and requires a separate license for commercial use.

Arasan says that over 75 customers use the AC21C00 SDIO chip to build SDIO cards such as Bluetooth, GPS, RFID, and Zigbee interfaces. The company also offers a Standard SDIO Host Platform that can be used for production testing.

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