Cancellation of redundant elements with a cancel bank

A cancel bank, comprising:

• a set of cancel switches;
• and
• a selection circuit,
• wherein the selection circuit includes a number of inputs and a number of outputs greater than the number of inputs,
• wherein each of the inputs is coupled to one of the cancel switches,
• wherein each of the outputs is adapted to be coupled to a switch bank that is adapted to be programmed to replace a defective primary element with a predetermined redundant element, and
• wherein the selection circuit provides a cancel signal on one of the outputs to disable a selected programmed switch bank from replacing a defective primary element with a defective redundant element.

A cancel bank, comprising:

• a set of n cancel switches;
• and
• a selection circuit,
• wherein the selection circuit includes n inputs and 2n outputs,
• wherein the n inputs are coupled to the set of n cancel switches,
• wherein each of the 2n outputs is adapted to be coupled to a switch bank that is adapted to be programmed to replace a defective primary element with a predetermined redundant element, and
• wherein the selection circuit provides a cancel signal on one of the 2n outputs to disable a selected programmed switch bank from replacing a defective primary element with a defective redundant element.

An integrated circuit, comprising:

• a plurality of redundant elements adapted to replace defective primary elements;
• a plurality of switch banks, each switch bank being adapted to be permanently programmed to replace a defective primary element with a predetermined redundant element;
• and
• a plurality of cancel banks, wherein each cancel bank includes:
• a number of cancel switches adapted to provide a coded signal;
• and
• a decoder having a number of selection outputs greater than the number of cancel switches, the decoder being adapted to receive the coded signal on one of the selection outputs and decode the coded signal into a cancel signal for a selected switch bank that was programmed to replace a defective primary element with a predetermined redundant element, wherein the cancel signal disables the selected switch bank from replacing a defective primary element with a defective redundant element.

An integrated circuit, comprising:

• a plurality of redundant elements adapted to replace defective primary elements;
• a plurality of switch banks organized in switch bank sets, each switch bank being adapted to be programmed to replace a defective primary element with a predetermined redundant element;
• and
• a plurality of cancel banks adapted to disable a switch bank such that a programmed switch bank does not replace a defective primary element with a defective redundant element, wherein each cancel bank is coupled to a switch bank set and to a number of cancel select lines, and wherein the number of cancel select lines is less than the number of switch banks in each switch bank set.

A method for canceling a programmed switch bank that has replaced a defective primary element with a defective redundant element, comprising:

• organizing a plurality of switch banks into switch bank sets, wherein each of the plurality of switch bank sets includes 2n switch banks, and wherein each of the plurality of switch banks is coupled to a redundant element;
• providing a coded cancel signal using a set of n cancel switches for each of the switch bank sets;
• and
• decoding the coded cancel signal to produce a cancel signal on one of 2n outputs to disable a selected one of the 2n switch banks that has replaced a defective primary element with a defective redundant element.