MV1442

The MV1442, along with other devices in the Zarlink 2MbitPCM signalling series comprise a group of circuits which willperform the common channel signalling and error detectionfunctions for a 2.048Mbit PCM transmission link operating inaccordance with the appropriate CCITT recommendations.The circuits are fabricated in CMOS and operate from asingle +5V supply with all inputs and outputs being TTLcompatible.

The MV1442 is an encoder/decoder for the HDB3 pseudo-ternary transmission code, described in Annex A of CCITTRecommendation G.703. The device encodes and decodessimultaneously and asynchronously. Error monitoringfunctions are provided to detect violations of the HDB3coding, all ones detection and loss of input (all zeros detection)In addition a loop back function is provided for terminaltesting. The MV1442 may be selected to function in eitherinternal or external clock recovery modes. Internal clockrecovery mode may be selected tor either 1.544MHz or2.048MHz operation and in this mode an external 16.384MHzcrystal (12.352MHz for 1.544MHz operation) is required.External clock recovery mode may be selected for 1.544MHz,2.048MHz or 8.448MHz operation.