PARALLEL DISTRIBUTED SAMPLING DESCRAMBLING CIRCUIT FOR DESCRAMBLING CELL-BASE PARALLEL ASYNCHRONOUS TRANSMISSION MODE PHYSICAL LAYER

摘要

PURPOSE: To process parallelly distributed samples for an ATM physical layer at a slower operation speed by processing transmission data parallelly for 8 bits by using a common semiconductor element. CONSTITUTION: When an optional value not '0' is set by using initial value setting signals SETB at the time of initialization, a PRBS generator 22 generates the random number of the 8 bits for executing a prescribed generating polynomial (X<31> +X<28> +1) for distributed sample descrambling. A descrambler 21 adds output signals PN7-PN0 from the generator 22, performs descrambling and then, outputs the next descrambled data TD7-TD0. A sample processor 23 extracts a second bit which is ATM cell data in the random number to be added to a fifth octet and a sixth bit in the random number to be added to a 31st octet and outputs synchronizing signals CRR1 and CRR0 for synchronizing the generator 22.