Redundant column or row in resistive random access memory

A resistive random access memory (RRAM) array to support a redundant row comprising:

• a plurality of row lines;
• a plurality of column lines perpendicular to the plurality of row lines, wherein a cross point is formed at each location where a row line of the plurality of row lines crosses a column line of the plurality of column lines;
• an RRAM cell at each cross point;
• a plurality of switches coupled to the plurality of row lines, wherein a first row line of the plurality of row lines is coupled to a first switch of the plurality of switches, a last row line of the plurality of row lines is coupled to a last switch of the plurality of switches, and each of a remainder of row lines of the plurality of row lines is coupled to two switches of the plurality of switches;
• a plurality of row select signals, wherein each switch of the plurality of switches is coupled to a row select signal of the plurality of row select signals;
• and
• a plurality of drivers, wherein each switch is coupled to a driver.

A method of manufacturing a resistive random access memory (RRAM) array that supports a redundant column comprising:

• fabricating a plurality of row lines;
• fabricating a plurality of column lines perpendicular to the plurality of row lines, wherein the plurality of column lines has n+1 column lines and a cross point is formed at each location where a row line of the plurality of row lines crosses a column line of the plurality of column lines;
• fabricating an RRAM cell at each cross point;
• coupling n current-steering multiplexers to the plurality of column lines, wherein each current-steering multiplexer is coupled to two column lines of the plurality of column lines, has a select input coupled to a column select signal, and has a bidirectional node coupled to a current sense amplifier;
• identifying a failed column line;
• and
• based on the identification of the failed column line,
• applying a low column select signal at the select input of each current-steering multiplexer coupled to the column line of the plurality of column lines prior to the failed column line to select each column line of the plurality of column lines to the left of the failed column line, and
• applying a high column select signal at the select input of each current-steering multiplexer coupled to the column line of the plurality of column lines after the failed column line to select each column line of the plurality of column lines to the right of the failed column line.

A resistive random access memory (RRAM) array to support a redundant column comprising:

• a plurality of row lines;
• a plurality of column lines perpendicular to the plurality of row lines, wherein a cross point is formed at each location where a row line of the plurality of row lines crosses a column line of the plurality of column lines;
• an RRAM cell at each cross point;
• a plurality of current-steering multiplexers coupled to the plurality of column lines, wherein a first column line of the plurality of column lines is coupled to a first current-steering multiplexer of the plurality of current-steering multiplexers, a last column line of the plurality of column lines is coupled to a last current-steering multiplexer of the plurality of current-steering multiplexers, and each of a remainder of column lines of the plurality of column lines is coupled to two current-steering multiplexers of the plurality of current-steering multiplexers;
• a plurality of current sense amplifiers, wherein each current-steering multiplexer has an output coupled to a current sense amplifier of the plurality of current sense amplifiers;
• and
• a plurality of column select signals, wherein each current-steering multiplexer of the plurality of current-steering multiplexers is coupled to a column select signal of the plurality of column select signals.