Overview
The ISDN PC Adapter Circuit Extended IPAC-X integrates all necessary functions for a host based ISDN access solution on a single chip. It is based on the IPAC PSB 2115, and provides enhanced features and functionality.
It includes the S-transceiver (Layer 1), an HDLC controller for the D-channel and two protocol controllers for each B-channel. They can be used for HDLC protocol or transparent access.

FEATUREs
• Single chip host based ISDN solution
• Based on IPAC PSB 2115, integrating ISAC-S and HSCX-TE functionality
• 8-bit parallel microcontroller interface, Motorola and Siemens/Intel bus type multiplexed or non-multiplexed, direct-/indirect register addressing
• Serial control interface (SCI)
• Microcontroller access to all IOM-2 timeslots
• Various types of protocol support (Non-auto mode, transparent mode, extended transparent mode)
• B-channel HDLC controllers with 128 byte FIFOs
• Flexible access to 18-bit timeslots (2B+D) on IOM-2 for IDSL support
• D-channel HDLC controller with 64 byte FIFOs
• IOM-2 interface in TE, LT-T, LT-S and NT mode, single/double clocks and two strobe signals
• D-channel priority handler on IOM-2 for intelligent NT applications
• Monitor channel handler (master/slave)
• IOM-2 MONITOR and C/I-channel protocol to control peripheral devices
• Full duplex 2B+D S/T-interface transceiver according to ITU-T I.430
• Conversion of the frame structure between the S/T-interface and IOM-2
• Receive timing recovery
• D-channel access control
• Activation and deactivation procedures with automatic activation from power down state
• Access to S and Q bits of S/T-interface