Writable tracking cells

A multi-state memory comprising:

• a plurality of multi-state memory cells, each for storing one of a plurality N of multi-states;
• a plurality M of populations of tracking cells, wherein each of said populations is associated with one of said multi-states;
• and
• a read circuit for reading said multi-state memory cells using read points for distinguishing between adjacent states of said plurality of multi-states based upon threshold voltages read from said populations of tracking cells, wherein at least one of said read points is based upon threshold voltages from a population of tracking cells not associated with the adjacent states between which said at least one read point distinguishes.

A multi-state memory comprising:

• a plurality of multi-state memory cells, each for storing one of a plurality N of multi-states;
• a plurality M of tracking cell populations, wherein each of said populations is associated with one of said multi-states;
• and
• a translation circuit for reading said multi-state memory cells using read points for each of said plurality of multi-states using the analog value of the programmed state of said tracking cell populations.

A non-volatile memory comprising:

• a plurality of memory cells, each for storing one of N states;
• a plurality of tracking cells, wherein each of said tracking cells is associated with one of said N states;
• a read circuit for reading said memory cells using read points for each of said N states based upon the threshold voltages associated with the programmed state of said tracking cells;
• and
• programming circuitry for programming said memory cells and said tracking cells, wherein at least one of said tracking cells is programmed by a different algorithm than a memory cell programmed to the associated one of said N states.

A method of operating a multi-state memory comprising:

• reading the threshold voltages of one or more multi-state memory cells, each for storing one of a plurality N of multi-states;
• reading the threshold voltages of a plurality M of populations of tracking cells, wherein each of said populations is associated with one of said multi-states, and wherein M is less than N;
• and
• converting the threshold voltages of said memory cells to logical values of said plurality of multi-states using the threshold voltages of said tracking cells.

A method of operating a multi-state memory comprising:

• reading the threshold voltages of one or more multi-state memory cells, each for storing one of a plurality N of multi-states;
• reading the threshold voltages of a plurality M of populations of tracking cells, wherein each of said populations is associated with one of said multi-states;
• establishing read points for distinguishing between adjacent states of said plurality of multi-states based upon the threshold voltages of said populations 10 of tracking cells, wherein at least one of said read points is based upon the threshold voltages from a population of tracking cells not associated with the adjacent states between which said at least one read point distinguishes;
• and
• converting the threshold voltages of said memory cells to logical values of said plurality of multi-states using said read points.

A method of operating a multi-state memory comprising:

• providing one or more multi-state memory cells, each for storing one of a plurality N of multi-states;
• providing a plurality M of tracking cell populations, wherein each of said populations is associated with one of said multi-states;
• and
• establishing (N−1) read points using the analog value of the programmed state of said tracking cell populations;
• and
• converting the threshold voltages of said memory cells to logical values of said plurality of multi-states using said read points.

A method of operating a non-volatile memory comprising:

• programming one or more memory cells, each for storing one of N states;
• programming a plurality of tracking cells, wherein each of said tracking cells is associated with one of said N states, wherein at least one of said tracking cells is programmed by a different algorithm than a memory cell programmed to the associated one of said N states;
• and
• converting the threshold voltages of said memory cells to logical values of said N states using the threshold voltages of said tracking cells.

An integrated circuit comprising:

• a plurality of multi-state memory cells, each for storing one of a plurality N of data states;
• a plurality of M reference voltage circuits, wherein each reference voltage circuit is associated with one of said N data states, and each comprising:
• a population of tracking cells;
• and
• a dedicated sense amp for each of said tracking cells connected to provide an analog voltage associated with the programmed state of the tracking to which it is connected;
• a read point circuit connected to said reference voltage circuits to receive said analog values and providing at least (N−1) voltage levels derived from said average values;
• and
• reading circuitry connected to receive said at least (N−1) voltage levels and connectable to said memory cells and providing the data state of a memory cell to which it is connected based on said at least (N−1) voltage levels.

A said sense amp for providing the analog voltage level of a non-volatile memory cell connected between said sense amp and ground, comprising:

• a first transistor connected between a voltage source and a first node and having a control gate connected to a reference voltage;
• a second transistor connected between said voltage source and a second node and having a control gate connected to said first node;
• a third transistor connected between said second node and ground;
• and
• an output for providing said analog voltage connected to said second node, wherein said memory cell is connected between said first node and ground and has a control gate connected to said second node.