DESCRIPTION:

The SA9101 (Frame Alignment unit for PCM30 Systems) is a C-MOS device which implements the interface to PCM30 Transmission Systems.

In the receive direction, the device performs HDB3 decoding, Frame alignment (selectable between doubleframe and CRC-Multiframe) and extraction of signalling data.

FEATURES

■ Frame alignment/synthesis for PCM30 double frame and CRC-multiframe format.

■ Meets CCITT Rec.G704

■ Interface to route selectable between HDB3 and fibre optical

■ HDB3 outputs switchable between fully bauded and half bauded format

■ Error checking via CRC4 procedure

■ Insertion and extraction of alarms and facility signals

■ Selectable system - clock (4096 kHz/8192 kHz)

■ Selectable Interface mode (2048/4096 kBit/s) to system internal highway

■ Programmable offsets for receive and transmit data

■ Two frame receive buffer for receive route clock wander and jitter compensation

■ Slip detection and direction indication

■ Extended HDB3 error detection

■ Error counters for code errors (switchable to "Sizeros counter"), frame errors and CRC4 errors

■ Sub-multiframe assigned CRC Error indication with possibility of automatic insertion in Si-bit position of outgoing multiframe.

■ Simplified data transfer between SA9101 and controller, supported by data stacks for receive and transmit signalling data, selectable interrupt sources and DMA facilities.

■ Double frame marker for serial data extraction support

■ Repeated transmission of signalling data, if not updated.

■ Three transparent modes for timeslot 0 in transmit direction

■ Transparent mode for receive direction

■ HDB3 error indication

■ Idle channel data insertion selectable for any timeslot

■ Channel loopback capabilities, test and diagnostic capabilities

■ Parity checks