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