It is claimed:
1. A method of operating a memory device, the method comprising:
connecting a first potential to source lines of memory cells of a first block of memory cells during an access operation; and
disconnecting a supply voltage from source lines of memory cells of a second block of memory cells during the access operation.
2. The method of claim 1, wherein connecting a first potential to source lines includes connecting the source lines to ground.
3. The method of claim 2, wherein the access operation is one of read operation and program operation.
4. The method of claim 1, wherein connecting a first potential to source lines includes connecting the source lines to a positive voltage.
5. The method of claim 4, wherein the access operation is an erase operation.
6. A method of operating a memory device, the method comprising:
setting source lines of memory cells of a first block of memory cells to a first state during an access operation; and
setting source lines of memory cells of a second block of memory cells to a second state during the access operation.
7. The method of claim 6, wherein setting source lines of memory cells of a first block of memory cells includes applying a non-zero voltage to the source lines of memory cells of the first block of memory cells.
8. The method of claim 7, wherein setting source lines of memory cells of a second block of memory cells includes applying ground to the source lines of memory cells of the second block of memory cells.
9. The method of claim 6, wherein setting source lines of memory cells of a first block of memory cells includes applying a voltage to the source lines of memory cells of the first block of memory cells.
10. The method of claim 9, wherein setting source lines of memory cells of a second block of memory cells includes setting the source lines of memory cells of the second block of memory cells to a high impedance state.
11. The method of claim 6, wherein setting source lines of memory cells of a first block of memory cells and setting source lines of memory cells of a second block of memory cells includes:
applying a first potential to the source lines of memory cells of the first block of memory cells.
applying a second potential to the source lines of memory cells of the second block of memory cells, wherein the first potential is unequal to the second potential.
12. A method of operating a memory device, the method comprising:
setting source lines of memory cells of a first block of memory cells to a first state during an erase operation; and
setting source lines of memory cells of a second block of memory cells to a second state during the erase operation, wherein the first state is unequal to the second state.
13. The method of claim 12, wherein setting source lines of memory cells of a first block of memory cells includes applying a positive voltage to the source lines of memory cells of the first block of memory cells.
14. The method of claim 13, wherein setting source lines of memory cells of a second block of memory cells includes applying ground to the source lines of memory cells of the second block of memory cells.
15. The method of claim 12, wherein setting source lines of memory cells of a first block of memory cells includes applying a voltage to the source lines of memory cells of the first block of memory cells.
16. The method of claim 15, wherein setting source lines of memory cells of a second block of memory cells includes setting the source lines of memory cells of the second block of memory cells to a high impedance state.
17. The method of claim 12, wherein setting source lines of memory cells of a first block of memory cells and setting source lines of memory cells of a second block of memory cells includes:
applying a first potential to the source lines of memory cells of the first block of memory cells.
applying a second potential to the source lines of memory cells of the second block of memory cells, wherein the first potential is unequal to the second potential.
18. A method comprising:
fabricating a plurality of horizontal source lines, each of the horizontal source lines having a resistance per unit length;
connecting the horizontal source lines together using a vertical source line;
connecting the horizontal source lines together at a plurality of horizontal locations using a plurality of vertical line straps; and
connecting the vertical source line to a global source line through a first plurality of switches.
19. The method of claim 18 further comprising: connecting the vertical source line to a source bus through a second plurality of switches.
20. The method of claim 18, wherein fabricating a plurality of the horizontal source lines includes fabricating the horizontal source lines with semiconductor material.
21. The method of claim 20, wherein connecting the horizontal source lines together using a vertical source line includes using metal for the vertical source line.
22. The method of claim 18, wherein fabricating a plurality of the horizontal source lines includes fabricating the horizontal source lines with doped polysilicon.
23. The method of claim 18, wherein connecting the horizontal source lines together using a vertical source line includes using material for the vertical source line different from material of the horizontal source lines.
24. A memory device comprising:
a first block having a first plurality of memory cells;
a first plurality of source lines connected to the first plurality memory cells;
a second block having a second plurality of memory cells;
a second plurality of source lines connected to the second plurality memory cells; and
a source line decoder circuit connected to the first plurality of source lines and the second plurality of vertical source lines for applying a first potential to the first plurality of source lines during an access operation, and for disconnecting a supply voltage from the second plurality of source lines during the access operation.
25. The memory device of claim 24, wherein the source line decoder circuit includes a first plurality of switches for connecting the first plurality of source lines and the second plurality of source lines to a global source line.
26. The memory device of claim 25, wherein the source line decoder circuit further includes a second plurality of switches for connecting the first plurality of source lines and the second plurality of source lines to a source bus.
27. A memory device comprising:
a first block having a first plurality of memory cells;
a first plurality of source lines connected to the memory cells of the first block;
a second block having a second plurality of memory cells;
a second plurality of source lines connected to the memory cells of the second block; and
a source line decoder circuit connected to the first plurality of source lines and the second plurality of source lines for setting the first plurality of source lines to a first state during an access operation, and for setting the second plurality of source lines to a second state during the access operation.
28. The memory device of claim 27, wherein the source line decoder circuit includes a first plurality of switches for connecting the first plurality of source lines and the second plurality of source lines to a global source line.
29. The memory device of claim 28, wherein the source line decoder circuit further includes a second plurality of switches for connecting the first plurality of source lines and the second plurality of source lines to a source bus.
30. The memory device of claim 27, wherein the source line decoder circuit includes a first plurality of switches for connecting the first group of vertical source lines to a global source line having a first potential during the access operation, and for connecting the second group of vertical source lines to a source bus having a second potential unequal to the first potential during the access operation.
31. The memory device of claim 27, wherein the source line decoder circuit includes a first plurality of switches for connecting the first group of vertical source lines to a global source line having a potential during the access operation, and for setting the second group of vertical source lines to a high impedance state during the access operation.
32. A memory device comprising:
a first block having a first plurality of memory cells;
a first plurality of source lines connected to the memory cells of the first block;
a second block having a second plurality of memory cells;
a second plurality of source lines connected to the memory cells of the second block; and
a source line decoder circuit connected to the first plurality of source lines and the second plurality of source lines for setting the first plurality of source lines to a first state during an erase operation, and for setting the second plurality of source lines to a second state unequal to the second state during the erase operation.
33. The memory device of claim 32, wherein the source line decoder circuit includes a first plurality of switches for connecting the first plurality of source lines and the second plurality of source lines to a global source line.
34. The memory device of claim 33, wherein the source line decoder circuit further includes a second plurality of switches for connecting the first plurality of source lines and the second plurality of source lines to a source bus.
35. The memory device of claim 32, wherein the source line decoder circuit includes a first plurality of switches for connecting the first group of vertical source lines to a global source line having a first voltage during the erase operation, and for connecting the second group of vertical source lines to a source bus having a second voltage unequal to the first voltage during the erase operation.
36. The memory device of claim 32, wherein the source line decoder circuit includes a first plurality of switches for connecting the first group of vertical source lines to a global source line having a positive voltage during the erase operation, and for connecting the second group of vertical source lines to a source bus having zero voltage during the erase operation.
37. The memory device of claim 32, wherein the source line decoder circuit includes a first plurality of switches for connecting the first group of vertical source lines to a global source line having a voltage during the erase operation, and for setting the second group of vertical source lines to a high impedance state during the erase operation.
38. A memory device comprising:
a plurality of horizontal source lines, each of the horizontal source lines having a resistance per unit length;
a plurality of vertical source lines connected to the horizontal source lines;
a plurality of vertical line straps connects the horizontal source lines together at a plurality of horizontal locations; and
a source line decoder circuit connected to the plurality of vertical source lines for applying a first potential to a first group of vertical source lines in the plurality of vertical source lines during an access operation, and for disconnecting a supply voltage from a second group of vertical source lines in the plurality of vertical source lines during the access operation.
39. The memory device of claim 38, wherein the source line decoder circuit includes a first plurality of switches connected between the plurality of vertical source lines and a global source line.
40. The memory device of claim 39, wherein the source line decoder circuit further includes a second plurality of switches connected between the plurality of vertical source lines and a source bus.
41. A memory device comprising:
a plurality of horizontal source lines, each of the horizontal source lines having a resistance per unit length;
a plurality of vertical source lines connected to the horizontal source lines;
a plurality of vertical line straps connects the horizontal source lines together at a plurality of horizontal locations; and
a source line decoder circuit connected to the plurality of vertical source lines for setting a first group of vertical source lines in the plurality of vertical source lines to a first state during an access operation, and for setting a second group of vertical source lines in the plurality of vertical source lines to a second state the access operation.
42. The memory device of claim 41, wherein the source line decoder circuit includes a first plurality of switches connected between the plurality of vertical source lines and a global source line.
43. The memory device of claim 42, wherein the source line decoder circuit further includes a second plurality of switches connected between the plurality of vertical source lines and a source bus.
44. The memory device of claim 41, wherein the source line decoder circuit includes a first plurality of switches for connecting the first group of vertical source lines to a global source line having a first potential during the access operation, and for connecting the second group of vertical source lines to a source bus having a second potential unequal to the first potential during the access operation.
45. The memory device of claim 41, wherein the source line decoder circuit includes a first plurality of switches for connecting the first group of vertical source lines to a global source line having a potential during the access operation, and for setting the second group of vertical source lines to a high impedance state during the access operation.
46. A memory device comprising:
a plurality of horizontal source lines, each of the horizontal source lines having a resistance per unit length;
a plurality of vertical source lines connected to the horizontal source lines;
a plurality of vertical line straps connects the horizontal source lines together at a plurality of horizontal locations; and
a source line decoder circuit connected to the plurality of vertical source lines for setting a first group of vertical source lines in the plurality of vertical source lines to a first state during an erase operation, and for setting a second group of vertical source lines in the plurality of vertical source lines to a second state the erase operation.
47. The memory device of claim 46, wherein the source line decoder circuit includes a first plurality of switches connected between the plurality of vertical source lines and a global source line.
48. The memory device of claim 47, wherein the source line decoder circuit further includes a second plurality of switches connected between the plurality of vertical source lines and a source bus.
49. The memory device of claim 46, wherein the source line decoder circuit includes a first plurality of switches for connecting the first group of vertical source lines to a global source line having a first voltage during the erase operation, and for connecting the second group of vertical source lines to a source bus having a second voltage unequal to the first voltage during the erase operation.
50. The memory device of claim 46, wherein the source line decoder circuit includes a first plurality of switches for connecting the first group of vertical source lines to a global source line having a non-zero voltage during the erase operation, and for connecting the second group of vertical source lines to a source bus having zero voltage during the erase operation.
51. The memory device of claim 46, wherein the source line decoder circuit includes a first plurality of switches for connecting the first group of vertical source lines to a global source line having a voltage during the erase operation, and for setting the second group of vertical source lines to a high impedance state during the erase operation.
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 treating a patient comprising:
implanting a cardioverter-defibrillator in the patient;
capturing far-field cardiac signals from electrodes disposed beneath the skin and outside of a patient’s ribcage;
identifying the patient’s P-wave in the far-field cardiac signals;
monitoring the patient’s P-wave to determine whether the patient’s P-wave abruptly changes; and
if the patient’s P-wave abruptly changes, determining that the patient is experiencing atrial fibrillation and withholding cardiac stimulus that would otherwise be delivered to the patient.
2. The method of claim 1, wherein the cardioverter-defibrillator comprises a lead assembly coupled to a canister that houses operational circuitry for the cardioverter-defibrillator, and the step of implanting comprises placing the canister and the lead assembly in the patient beneath the skin and outside of the patient’s ribcage without accessing the vasculature or heart of the patient.
3. The method of claim 1, further comprising withholding cardiac stimulus that would otherwise be delivered to the patient if it is determined that the patient is experiencing atrial fibrillation.
4. The method of claim 1, wherein the step of monitoring the patient’s P-wave includes determining whether the patient’s P-wave disappears and, if so, concluding that the P-wave has abruptly changed.
5. The method of claim 1, further comprising identifying at least one characteristic of the patient’s P-wave during normal sinus rhythm.
6. The method of claim 5, wherein the at least one characteristics of the patient’s P-wave includes the morphology of the patient’s P-wave during normal sinus rhythm, and further wherein an abrupt change is determined by observation of whether a change occurs in the morphology of the patient’s P-wave.
7. The method of claim 5, wherein the at least one characteristic of the patient’s P-wave includes the amplitude and timing relationship of the patient’s P-wave to the patient’s QRS during normal sinus rhythm, and further wherein an abrupt change is determined by observation of whether a change occurs in the amplitude and timing relationship of the patient’s P-wave to the patient’s QRS during an unknown rhythm.
8. The method of claim 5, wherein the at least one characteristic of the patient’s P-wave includes the frequency content of the patient’s P-wave during normal sinus rhythm, and further wherein an abrupt change is determined by observation of whether a change occurs in the frequency content of the patient’s P-wave.
9. The method of claim 5, wherein the at least one characteristic of the patient’s P-wave includes the timing of the patient’s P-wave in relation to the patient’s QRS during normal sinus rhythm, and further wherein an abrupt change is determined by observation of whether a change occurs in the timing of the patient’s P-wave in relation to the patient’s QRS.
10. The method of claim 5, wherein the at least one characteristic of the patient’s P-wave includes polarity of the patient’s P-wave in relation to the patient’s QRS during normal sinus rhythm, and further wherein an abrupt change is determined by observation of whether a change occurs in the polarity of the patient’s P-wave in relation to the patient’s QRS.
11. An implantable cardioverter defibrillator (ICD) comprising a housing containing operational circuitry that is coupled to a plurality of electrodes for implantation in a patient, wherein the operational circuitry is configured to perform the following method of cardiac signal analysis while implanted in a patient:
capturing far-field cardiac signals from electrodes disposed beneath the skin and outside of a patient’s ribcage;
identifying the patient’s P-wave in the far-field cardiac signals;
monitoring the patient’s P-wave to determine whether the patient’s P-wave abruptly changes; and
if the patient’s P-wave abruptly changes, determining that the patient is experiencing atrial fibrillation and withholding cardiac stimulus that would otherwise be delivered to the patient.
12. The ICD of claim 11, wherein the operational circuitry is further configured to withhold cardiac stimulus that would otherwise be delivered to the patient if it is determined that the patient is experiencing atrial fibrillation.
13. The ICD of claim 11, wherein the operational circuitry is further configured such that the step of monitoring the patient’s P-wave includes determining whether the patient’s P-wave disappears and, if so, concluding that the P-wave has abruptly changed.
14. The ICD of claim 11, wherein the operational circuitry is further configured such that the method also includes identifying at least one characteristic of the patient’s P-wave during normal sinus rhythm.
15. The ICD of claim 14, wherein the operational circuitry is further configured such that:
the at least one characteristic of the patient’s P-wave includes the morphology of the patient’s P-wave during normal sinus rhythm; and
an abrupt change is determined by observation of whether a change occurs in the morphology of the patient’s P-wave.
16. The ICD of claim 14, wherein the operational circuitry is further configured such that:
the at least one characteristic of the patient’s P-wave includes the amplitude and timing relationship of the patient’s P-wave to the patient’s QRS during normal sinus rhythm; and
wherein an abrupt change is determined by observation of whether a change occurs in the amplitude and timing relationship of the patient’s P-wave to the patient’s QRS.
17. The ICD of claim 14, wherein the operational circuitry is further configured such that:
the at least one characteristic of the patient’s P-wave includes the frequency content of the patient’s P-wave during normal sinus rhythm; and
an abrupt change is determined by observation of whether a change occurs in the frequency content of the patient’s P-wave.
18. The ICD of claim 14, wherein the operational circuitry is further configured such that:
the at least one characteristic of the patient’s P-wave includes the timing of the patient’s P-wave in relation to the patient’s QRS during normal sinus rhythm; and
an abrupt change is determined by observation of whether a change occurs in the timing of the patient’s P-wave in relation to the patient’s QRS.
19. The ICD of claim 14, wherein the operational circuitry is further configured such that:
the at least one characteristic of the patient’s P-wave includes polarity of the patient’s P-wave in relation to the patient’s QRS during normal sinus rhythm; and
an abrupt change is determined by observation of whether a change occurs in the polarity of the patient’s P-wave in relation to the patient’s QRS.
20. A method of identifying atrial fibrillation in an implantable cardiac stimulus device comprising:
capturing cardiac signals from electrodes disposed beneath the skin and outside of a patient’s ribcage;
identifying R-waves in the cardiac signals and observing whether intervals between R-waves are stable or irregular;
if the R-wave intervals are irregular, observing whether QRS morphology is similar on a beat-to-beat basis; and
if R-wave intervals are irregular and QRS morphology is similar on a beat-to-beat basis, determining that the patient is experiencing atrial fibrillation.