Altera is the only PLD manufacturer who employs this technology. Accordingly, it continues to be the lowest cost producer and delivers the best product margins in the PLD industry. Altera's Quartus software meets the challenges of designing for multi-million gate devices and enables SOPC design methodology. Altera has been using redundancy techniques in its PLDs for some time. Other semiconductor suppliers use the technique, but Altera is the only PLD producer using this yield-enhancing process.
Redundancy is most important when developing new processes and in very large chips.
These are the situations where it is much more likely to encounter chip-destroying defects in the manufacturing process. New processes always result in a higher defect density. The density of defects drops as the new process matures and process improvements are made. Larger chips are obviously more likely to encounter a defect than smaller devices. Altera tends to remove the redundancy circuits in devices as the process matures.