MT90225

The MT90225/226 device is targeted to systems implementing TC or UNI (User Network Interface) specifications for T1/E1 rates or DSL rates. In the MT90225/226 architecture, up to 16/8 physical and independent serial links can be terminated through the utilization of off-the-shelf, traditional T1/E1/J1 framers/LIUs and DSL chip sets.

The MT90225/226 device provides ATM system designers with a flexible architecture when implementing ATM access over existing trunk interfaces, allowing a migration towards ATM service technology. The MT90225/226 is compliant with ATM TC/UNI specifications for T1/E1 rates. The MT90225/226 can be configured to operate in different TDM modes to facilitate the implementation of ATM over T1/E1/DSL at both CPE and Central Office sites. The device allows for bandwidth scaleability through the use of the UTOPIA MPHY, Level 1 and Level 2 specification at rates up to 52Mhz.

Main functions that are implemented in the MT90225/226 device are:
• Utopia Level 1 or 2 PHY Interface
• Incoming HEC verification and correction (optional),
• Generation of a new HEC byte
• Format outgoing bytes into multi-vendor TDM formats
• Retrieve ATM Cells from the incoming multi-vendor TDM format
• Perform cell delineation
• Provide various counters to assist in performance monitoring
• Generation and insertion of Idle Cells; The Idle cells are pre-defined.
• Provide structured Interrupt scheme to report various events
• 16-bit microprocessor interface (adaptable to Intel or Motorola interfaces)
• loopbacks