DESCRIPTION
The DS2182A T1 line monitor chip is a monolithic CMOS device designed to monitor real-time performance on T1 lines. The DS2182A frames to the data on the line, counts errors, and supplies detailed information about the status and condition of the line. Large on-board counters allow the accumulation of errors for extended periods, which permits a single CPU to monitor a number of T1 lines. Output clocks that are synchronized to the incoming data stream are provided for easy extraction of S-Bits, FDL bits, signaling bits, and channel data. The DS2182A meets the requirements of ANSI T1.231.

FEATURES
■ Performs framing and monitoring functions
■ Supports Superframe and extended Superframe formats
■ Four on-board error counters
    - 16-bit bipolar violation
    - 8-bit CRC
    - 8-bit OOF
    - 8-bit frame bit error
■ Indication of the following
    - Yellow and blue alarms
    - Incoming B8ZS code words
    - 8 and 16 zero strings
    - Change-of-frame alignment
    - Loss-of-sync
    - Carrier loss
■ Simple serial interface used for configuration, control, and status monitoring
■ Burst mode allows quick access to counters for status updates
■ Automatic counter reset feature
■ Single 5V supply; low-power CMOS technology
■ Available in 28-pin DIP and 28-pin PLCC
■ The DS2182A is upward-compatible from the original DS2182

The DS2182A includes the following changes from the original DS2182:
■ Ability to count excessive zeros
■ Severely errored-framing-event indication
■ Updated AIS detection
■ Updated RCL detection
■ AIS and RCL alarm clear indications