Abstract: In accordance with some embodiments, the way in which the fuses are sensed and, particularly, their order may be made more random so that it is much more difficult to simply exercise the device and determine all the values of the storage elements within the fuse array. One result is a more secure storage device.

Abstract: In accordance with some embodiments, multiple blind debug passwords are provided. Each of a plurality of interested entities may have its own password and each password may unlock a specific set of features offered by an integrated circuit. In some embodiments each entity does not know the other passwords of the other entities. Potentially interested entities include an integrated circuit end customer, the original equipment manufacturer, the entity that provided the features to the integrated circuit and a conditional access provider. All debug features may be controlled solely via access to the debug tiers which are accessed by multiple debug passwords. Lower tier passwords are required in order to access higher tiers. Debug features may be separated into multiple tiers with more intrusive access requiring multiple debug passwords in order to gain access.

Abstract: In accordance with some embodiments, instead of providing replacement rows, an area within a fuse array may be reserved for storing addresses of bits that are defective. Then these bits can be readily repaired by simply reading the stored state of identified defective bit, and inverting the stored state of the identified defective bit to get the correct output.

Abstract: In one embodiment described herein, on-die programmable fuses may be used. On-die programmable fuses may be programmed by entities other than the chip manufacturer after the fuse array chip has been manufactured and shipped out. However, other non-volatile memories may also be used.

Abstract: In accordance with some embodiments, multiple blind debug passwords are provided. Each of a plurality of interested entities may have its own password and each password may unlock a specific set of features offered by an integrated circuit. In some embodiments each entity does not know the other passwords of the other entities. Potentially interested entities include an integrated circuit end customer, the original equipment manufacturer, the entity that provided the features to the integrated circuit and a conditional access provider. All debug features may be controlled solely via access to the debug tiers which are accessed by multiple debug passwords. Lower tier passwords are required in order to access higher tiers. Debug features may be separated into multiple tiers with more intrusive access requiring multiple debug passwords in order to gain access.

Abstract: In one embodiment described herein, on-die programmable fuses may be used. On-die programmable fuses may be programmed by entities other than the chip manufacturer after the fuse array chip has been manufactured and shipped out. However, other non-volatile memories may also be used.

Abstract: In accordance with some embodiments, instead of providing replacement rows, an area within a fuse array may be reserved for storing addresses of bits that are defective. Then these bits can be readily repaired by simply reading the stored state of identified defective bit, and inverting the stored state of the identified defective bit to get the correct output.

Abstract: In accordance with some embodiments, the way in which the fuses are sensed and, particularly, their order may be made more random so that it is much more difficult to simply exercise the device and determine all the values of the storage elements within the fuse array. One result is a more secure storage device.