GENERAL DESCRIPTION
The Winbond's single chip USB bus ISDN S/T interface controller W6694 is an all-in-one device suitable for ISDN Internet access. The integrated USB and ISDN design provides low cost, pure passive solution for USB-IDSN application. W6694 also provides two PCM CODEC interfaces for the ability to access ISDN through voice channel.

FEATURES
ISDN
· Full duplex 2B+D S/T-interface transceiver compatible with ITU-T I.430 Recommendation
- Four wire operation
- Received clock recovery
- Layer 1 activation/deactivation procedure
- D channel access control
· Transparent data transmission of 2B+D channels
· Test functions
USB
· USB Specification version 1.0/1.1 compliant
· Full-speed, bus-powered USB device
· Integrated transceiver, PLL, SIE, SIL and voltage regulator
· Built-in fully automatic enumeration procedure
· Support suspend mode
- Suspend current requirement
- Wake-up by ISDN (remote) and PC (host)
Other Features
· GCI bus interface (slave mode) for connecting to ISDN U transceiver chip.
· PCM port provides two 64K clear channels to connect to PCM CODEC chips.
· B channel data switching function for selective connection between ISDN/GCI interface, USB and PCM.
· EEPROM interface for retrieving customized USB device identification data.
· IO pins with LED current drive capability.
· Reset pin for whole-chip reset.