Description

The MT8977 is a variant of the MT8976 framer, which has been enhanced to meet ACCUNET® T1.5 wander tolerance (138 UI).

The MT8977 meets ESF and D3/D4 formats, and is compatible with SLC-96 systems.

Features

• D3/D4 or ESF framing and SLC-96 compatible

• Two frame elastic buffer with jitter tolerance improved to 156 UI

• Insertion and detection of A, B, C, D bits, signalling freeze, optional debounce

• Selectable B8ZS, jammed bit (ZCS) or no zero code suppression

• Yellow alarm and blue alarm signal capabilities

• Bipolar violation count, FT error count, CRC error count

• Selectable robbed bit signalling

• Frame and superframe sync. signals, Tx and Rx

• AMI encoding and decoding

• Per channel, overall, and remote loop around

• Digital phase detector between T1 line and ST-BUS

• One uncommitted scan point and drive point

• Pin compatible with MT8976 and MT8979

• ST-BUS compatible

Applications

• DS1/ESF digital trunk interfaces

• Computer to PBX interfaces (DMI and CPI)

• High speed computer to computer data links