The ST7554 is a single chip host signal processing Modem/fax/voice controller that supports data rates up to 56Kbps. All data pump and protocol functions are executed on the host PC's processor. This product has been developed in cooperation with Smart Link Ltd, who ported "USB-Modio", its host based Modem and system software into ST system and hardware platform. The ST7554 directly connects to ST high performance Modem analog frontend (MAFE) STLC7550 or to the highly integrated MAFE+DAA chip-set ST75951/ST952. The ST7554 also features an Universal Serial Bus (USB) interface for direct connection to the host PC for maximum flexibility and real plug & play operation.