1. A memory device, comprising:
a plurality of physical blocks that each include a number of memory elements programmable between at least two different impedance states, the memory elements being subject to degradation in performance; and
bias circuits configured to applying healing electrical conditions to at least one spare physical block that does not contain valid data; wherein
the healing electrical conditions are different from write operation electrical conditions, and reverse degradation of the memory elements of the at least one spare physical block.
2. The memory device of claim 1, wherein:
the memory elements comprise a programmable resistance material formed between two electrodes.
3. The memory device of claim 2, wherein:
the memory elements each comprise a solid state electrolyte in which conductive regions can be formed and dissolved.
4. The memory device of claim 1, further including:
a wear circuit configured to generate a heal indication for a physical block in response to predetermined wear conditions; and
the bias circuits apply the healing electrical conditions to the physical block in response to at least the heal indication.
5. The memory device of claim 4, wherein:
the wear circuit is coupled to receive write request data, and includes a wear level store circuit to store wear level data for each physical block; wherein
the heal indication is generated in response to the wear level data for the physical blocks.
6. The memory device of claim 4, wherein:
the wear circuit includes a characterization circuit that applies characterization conditions to at least one element of the physical block to generate state data; and
the heal indication is generated in response to the state data.
7. The memory device of claim 1, wherein:
each physical block comprises a plurality of memory cells, each cell include
an access device coupled to a bit line common to a column of memory cells, and a word line common to a row of memory cells, and
at least one of the memory elements.
8. A system, comprising:
a plurality of memory blocks, each including a plurality of memory cells having at least one element programmable between impedance states, the memory blocks including active blocks and at least one spare block;
an address translation circuit configured to substitute accesses to one memory block for accesses to another memory block; and
a bias circuit configured to applying healing electrical conditions to the spare block; wherein
the healing electrical conditions are different from write conditions that write data to the memory cells and different from read conditions that read data from the memory cells, and reverse wear conditions of memory elements in the spare block.
9. The system of claim 8, wherein:
the memory elements are two terminal elements programmable to form and dissolve a conductive path though at least one memory layer.
10. The system of claim 8, wherein:
the memory blocks and address translation circuit are formed in a same integrated circuit (IC), and the address translation circuit translates address values received a source external to the IC into physical addresses that access the memory blocks.
11. The system of claim 8, wherein:
the memory blocks are formed in one integrated circuit (IC); and
the address translation circuit is formed in another IC.
12. The system of claim 8, wherein:
a control circuit configured to transfer data from one memory block to the spare block and designated the one memory block as the new spare block.
13. The system of claim 8, further including:
the memory blocks and bias circuit are formed in a same integrated circuit (IC);
a control circuit formed in the IC configured to generate heal control signals; and
the bias circuit is configured to apply the healing electrical conditions in response to the heal control signals.
14. The system of claim 8, wherein:
the memory blocks and bias circuit are formed in a same integrated circuit (IC); and
the bias circuit is configured to apply the healing electrical conditions in response to commands received by the IC.
15. A method, comprising:
determining a wear status each of a plurality of blocks, each block including a plurality of memory cells having at least one element programmable between impedance states;
if a block is determined to be worn, transferring data from the one block to a spare block; and
applying healing electrical conditions to the one block that reverse degradation of the memory elements of the worn block.
16. The method of claim 15, wherein:
determining the wear status includes storing a wear value for each block that corresponding to the number of times the block has been subject to at least one type of access operation.
17. The method of claim 15, wherein:
the healing electrical conditions are different from write conditions that write data into the cells.
18. The method of claim 15, further including:
designating the one block as a new spare block for receiving data from a next block determined to be worn.
19. The method of claim 15, further including:
after transferring data from the one block to the spare block, accessing the spare block with logical addresses previously used to access the one block.
20. The method of claim 15, wherein:
translating received logical addresses into physical addresses to access less than all of the blocks.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A method of forming encapsulated bichromal balls, said method comprising:
providing electrophoretic particles;
blending said particles with (i) a dielectric fluid, and (ii) an effective amount of a gelating agent;
providing a shell material;
forming capsules by encapsulating said particles, dielectric fluid, and gelating agent within a shell of said shell material;
heating said capsules to an elevated temperature;
applying a field to said capsules to separate the particles;
cooling said capsules to thereby cause gelling within said capsule while said field is maintained;
removing said field.
2. The process of claim 1, wherein said dielectric fluid is selected from the group consisting of partially fluorinated hydrocarbons, isoparaffins, polydimethyl siloxane oils, vegetable oils, and combinations thereof.
3. The process of claim 1, wherein said gelating agent is selected from the group consisting of materials capable of gelling hydrophobic organic liquids.
4. The process of claim 3, wherein said gelating agent includes trans-4-t-butyl-1-phenyl-cyclohexanol and derivatives.
5. The process of claim 1, wherein said heating is performed to a temperature of from about 35\xb0 C. to about 100\xb0 C.
6. The process of claim 1, wherein said heating is performed to a temperature of from about 35\xb0 C. to about 70\xb0 C.
7. The process of claim 1, wherein said electrophoretic particles are pigments selected from the group consisting of titania, carbon black, and combinations thereof.
8. The process of claim 1, wherein said electrophoretic particles are composite particles of a pigment and a resin, wherein said pigment is selected from the group consisting of rutile titania, anatase titania, barium sulfate, zinc oxide, carbon black, Sudan blue, Hostaperm pink, and combinations thereof.
9. The process of claim 1, wherein said shell material is selected from the group consisting of polyphosphates, polycarboxylates, and combinations thereof.
10. The process of claim 1, wherein said particles exhibit two colors.
11. The process of claim 7, wherein said resin is selected from the group consisting of polyethylene, polypropylene, copolymers of polyethylene and polypropylene, ethylene-vinyl acetate copolymers, and combinations thereof.
12. The process of claim 1, wherein said electrophoretic particles include fine powdered magnetic materials selected from the group consisting of ferrite, nickel, cobalt, iron, oxides thereof, and combinations thereof.
13. The process of claim 1, wherein said capsules have a size of from about 2 microns to about 750 microns.
14. The process of claim 12, wherein said capsules have a size of from about 5 to about 200 microns.
15. The process of claim 13, wherein said capsules have a size of from about 10 microns to about 120 microns.
16. The process of claim 1, wherein said gelating agent is present in a concentration of from about 0.1% to about 10% by weight of said dielectric fluid.
17. The process of claim 1, wherein said effective amount of said gelating agent is from about 0.5% to about 5% by weight of said dielectric fluid.
18. The process of claim 1, wherein said field applied to the capsules is a field selected from the group consisting of electronic, magnetic, and gravitational fields.
19. The encapsulated bichromal balls produced by the process of claim 1.
20. A display device produced with the encapsulated bichromal balls of claim 18.