Built-in self repair for memory

A memory having a built-in self-repair (BISR) circuit that is configured to perform a set of operations, the set of operations comprising:

• running a built-in self test of the memory to find faulty bits;
• selecting a first faulty bit of the faulty bits;
• calculating a first repair result using a redundant row block after selecting the first faulty bit;
• calculating a second repair result using a redundant column block after selecting the first faulty bit;
• comparing the first repair result and the second repair result;
• selecting a repair method using either the redundant row block or the redundant column block;
• and
• repairing the memory by replacing a row block having the first faulty bit with the redundant row block or replacing a column block having the first faulty bit with the redundant column block,
• wherein selecting the repair method comprises selecting the repair method which results in a fewest number of remaining faulty bits after repairing the memory, and the fewest number of remaining faulty bits after repairing the memory is greater than zero.

A computer-readable storage medium having instructions stored thereon, the instructions when executed by a processor causing the processor to perform operations of:

• running a built-in self test of the memory to find faulty bits;
• selecting a first faulty bit of the faulty bits;
• calculating a first repair result using a redundant row block after selecting the first faulty bit, wherein calculating the first repair results comprises determining a number of faulty bits not impacted using the redundant row block;
• calculating a second repair result using a redundant column block after selecting the first faulty bit, wherein calculating the second repair results comprises determining a number of faulty bits not impacted using the redundant column block, wherein at least one of the number of faulty bits not impacted using the redundant column block or the number of faulty bits not impacted using the redundant row blow is greater than zero;
• comparing the first repair result and the second repair result;
• selecting a repair method using either the redundant row block or the redundant column block;
• and
• repairing the memory by replacing a row block having the first faulty bit with the redundant row block or replacing a column block having the first faulty bit with the redundant column block, wherein repairing the memory comprises iteratively repairing the memory until the number of faulty bits not impacted using the redundant column block and the number of faulty bits not impacted using the redundant row blow is zero.