Redundant circuit for memory device

A redundant circuit comprising:

• a replacement circuit configurable to replace a defective circuit;
• and
• a support circuit coupled to the replacement circuit and configurable to provide a control signal for the replacement circuit, wherein the support circuit includes
• a first circuit having included therein at least one anti-fuse, wherein the first circuit is further configurable to program the at least one anti-fuse or sense a state of the at least one anti-fuse, and
• a second circuit coupled to the first circuit and including at least one fuse, wherein the second circuit is further configurable to sense a state of the at least one fuse, receive the sensed state of the at least one anti-fuse, and provide a programmed value indicative of the sensed states of the at least one fuse and the at least one anti-fuse.

A redundant circuit for a memory device, comprising:

• a redundant memory cell configurable to replace a defective memory cell;
• a first circuit configurable to provide a programmed address for the redundant memory cell, wherein the first circuit includes a set of fuses and a set of anti-fuses programmable to provide the programmed address;
• and
• an address comparator operatively coupled to the first circuit and the redundant memory cell, the address comparator configured to compare the programmed address and an external address and activate a control line for the redundant memory cell based at least in part on a result of the compare.

A method for programming a replacement circuit to replace a defective circuit, the method comprising:

• if replacement of the defective circuit with the replacement circuit is selected, programming a set of fuses or a set of anti-fuses to provide a programmed value for the replacement circuit, wherein the programming includes
• programming the set of fuses if the replacement circuit is selected to replace the defective circuit at a first time instant,
• determining whether or not the set of fuses has been programmed, and
• programming the set of anti-fuses if the replacement circuit is selected to replace the defective circuit at a second time instant and the set of fuses has not been programmed.

A method for replacing a defective circuit with a replacement circuit, the method comprising:

• sensing a programmed value for the replacement circuit, wherein the programmed value is indicative of states of a set of fuses and a set of anti-fuses previously programmed for the replacement circuit;
• providing an indication to activate the replacement circuit based at least in part of the programmed value;
• and
• activating the replacement circuit in response to the received indication.