Pipelined combined system for producing error correction code symbols and error syndromes for large ecc redundancy

Abstract

An n-stage pipelined combined encoder and syndrome generator system includes n stages that are essentially identical. Each of the stages includes two associated delay circuits, namely, a first delay circuit in a chain of feedback adders that operate as a feedback path during encoding, and a second delay circuit in a data input line. During encoding operations, the delay circuits in the feedback adder chain segment the chain of j feedback adders into n stages of j/n adders, and the delay circuits in the data input line delay the data symbols by the latencies associated with the respective stages. The delay circuits thus simultaneously provide to the various stages the corresponding data symbols and propagating sums. After the last data symbol is encoded, the ECC symbols are available after a time lag associated with the j/n adders in the last stage. During syndrome generation operations, the feedback adders are essentially decoupled from one another by AND gates that are included in the feedback path and switches in the data input line bypass the delay circuits, to avoid introducing latency into the syndrome generation operations.