Design and performance of a VLSI 120 Mb/s trellis-coded partial response channel

A VLSI trellis-coded partial-response (TCPR) codec module incorporating circuitry for three exploratory, improved trellis codes is presented. The architecture, implementation, and performance evaluation of a "partitioned" rate 8/10 matched-spectral-null (MSN) code are described in detail. The detector implementation uses a programmable, systolic architecture to realize a time-varying Add-Compare-Select (ACS) topology that rotates state-ACS assignments and periodically superimposes "auxiliary" survivor paths. The survivor memory unit requires only 3 bytes per interleave and is implemented using a two-stage, time-varying architecture combining register-exchange and traceback methods. The module was fabricated in 0.45 micron CMOS technology requiring less than 300 mW at 12 MB/sec. Selected experimental results for a variety of magnetic recording components are shown.< >