[comtech aha corporation] 311 MBITS/SEC TURBO PRODUCT CODE ENCODER/DECODER The AHA4541 device is a single-chip Turbo Product Code (TPC) Forward Error Correction (FEC) Encoder/Decoder capable of 311 Mbit/sec data rates (up to 360 Mbit/sec channel rates). This device integrates both a TPC encoder and decoder, and can be operated in a full duplex mode. In addition to TPC coding, support is included for helical interleaving, synchronization mark insertion and detection, CRC computation, scrambling, and higher order modulation symbol mapping. Figure 1 shows the functional block diagram. FEATURES PERFORMANCE: • Maximum 360 Mbit/sec channel rate • Payload data rates of at least 311 Mbit/sec for code rates >0.86 • Symbol rates up to 90 MSym/sec • Encode Latency of less than 10 clocks • Integrated encoder/decoder; scrambler/descrambler; and interleaver/deinterleaver for full duplex operation • Supports enhanced Turbo Product Codes (eTPCs) • Corrections count and averaging for channel SNR estimation FLEXIBILITY: • Code Rates from .25 to 0.98 • Variable iterations up to 256 per block • Block Sizes from 256 bits to 16 Kbits • Programmable code shortening supports exact block sizes • 32 bit CRC Insertion and Checking with programmable packet length CHANNEL INTERFACE: • Accepts in-phase and quadrature (I & Q) inputs, up to 8 bits each • Supports soft metric inputs at up to 4 soft metrics of 4 bits each • Soft metric computation for BPSK, QPSK, 8- PSK, 16-QAM, 64-QAM, and 256-QAM • Supports additional modulation formats with external logic • Encoder and decoder pass through modes • Programmable packet and block level synchronization • Automatic phase ambiguity resolution • Supports insertion and detection of sync marks up to 32 bits in length • 8-bit Parallel Data Input/Output • Support for external VCO to generate data clocks OTHERS: • Intel or Motorola microprocessor interface • 3.3V I/O, 1.8V core operation • Commercial or Industrial temperature rating
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