Introduction The Advanced CMOS Frame Aligner PEB 2035 (ACFA) is a monolithic CMOS device which implements the interface to primary rate PCM carriers. It may be programmed to operate in 24- channel (T1) and 32-channel (CEPT) carrier systems. Features Serial Interface to Line Interface Unit ● Frame alignment/synthesis for 2048 kbit/s (CEPT, PCM 30) and 1544 kbit/s (T1, PCM 24) ● Meets newest CCITT Rec’s (Blue Book), FTZ Rec’s and AT&T technical advisories (DMI, August 1986) ● Programmable formats for PCM 30: Doubleframe, CRC Multiframe PCM 24: 4-Frame Multiframe (F4), 12-Frame Multiframe (F12, D3/4), Extended Superframe (ESF), Remote Switch Mode (F72) ● Selectable conditions for loss of sync ● Selectable line codes (HDB3, B8ZS, AMI with ZCS) ● Unipolar NRZ for interfacing fibre optical transmission routes ● Error checking via CRC4 or CRC6 procedures ● Insertion and extraction of alarms and facility signaling ● IDLE code insertion for selectable channels Serial Interface to System Internal Highway ● System clock frequency of either 4096 kHz or 8192 kHz ● Selectable 2048/4096 kbit/s system internal highway with programmable receive/transmit shifts ● Two-frame deep elastic receive memory for receive route clock wander and jitter compensation (can be reduced to one-frame length for PCM 30 master-slave applications) ● One frame elastic transmit memory (PCM 24 mode only) for transmit route clock wander and jitter compensation ● Two different time-slot assignment procedures in PCM 24 mode ● Support for different signaling schemes ● Channel loop back capabilities ● Channel parity error monitoring ● Clear channel capabilities in PCM 24 mode Microprocessor Interface ● Parallel, demultiplexed microprocessor interface for random access to control and status registers ● Alarm interrupt capabilities ● Access to different signaling information: – Sa-, E, Si -bits (register) – Sa-bits (5-byte stack) – FDL bits with the possibility of mixed insertion – CCS, CAS-CC (common channel), CAS-BR (bit robbing) via 2/3-byte stacks with DMA/ interrupt support ● Extensive test and diagnostic capabilities General ● Advanced CMOS technology ● Low power consumption (< 100 mW) ● Packaging: P-DIP-40, P-LCC-44
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