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 many 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.