Claims
- 1. A microcomputer formed on a single semiconductor chip comprising:a CPU; a nonvolatile memory having a plurality of memory cells each of which includes a capacitor including a ferroelectric; and a designation circuit which designates a boundary which divides said nonvolatile memory into a nonvolatile memory area and a volatile memory area, wherein a rewrite operation of data stored to memory cells in said nonvolatile memory area is prevented and a rewrite operation of data stored to memory cells in said volatile memory area is permitted, and wherein electric polarization of said ferroelectric of each of said plurality of memory cells occurs by electric field and each of said plurality of memory cells stores data by a direction of electric polarization.
- 2. A microcomputer according to claim 1, wherein said nonvolatile memory area stores a program to be performed with said CPU.
- 3. A microcomputer according to claim 2, wherein said designation circuit includes a register and a comparator,wherein said register stores information for indicating said boundary of said nonvolatile memory area and said volatile memory area, and wherein said comparator compares said information with an address signal outputted from said CPU and outputs a write inhibit signal when an address signal outputted from said CPU is an address of said nonvolatile memory area.
- 4. A microcomputer according to claim 3, wherein said designation circuit includes a logic circuit which ignores a write control signal outputted from said CPU when said write inhibit signal is outputted from said comparator.
- 5. A microcomputer according to claim 4, wherein each of memory cells in said volatile memory area operates as a dynamic memory cell.
- 6. A microcomputer according to claim 5, wherein each of memory cells in said nonvolatile memory area operates as a read only memory cell.
- 7. A microcomputer according to claim 6, wherein a read operation for reading data stored in each of said memory cells in said nonvolatile memory area is performed without changing a polarity direction of said ferroelectric.
- 8. A microcomputer according to claim 7, wherein said information for indicating said boundary is set when a predetermined operation is confirmed in a debug mode.
- 9. A microcomputer according to claim 8, wherein said ferroelectric is PZT (PbZrTiO).
- 10. A semiconductor integrated circuit device formed on a single semiconductor chip comprising:a CPU; a nonvolatile memory having a plurality of memory cells each of which includes a capacitor including a ferroelectric; and a designation circuit which designates a boundary which divides said nonvolatile memory into a nonvolatile memory area and a volatile memory area, wherein a rewrite operation of data stored to memory cells in said nonvolatile memory area is prevented and a rewrite operation of data stored to memory cells in said volatile memory area is permitted, and wherein electric polarization of said ferroelectric of each of said plurality of memory cells occurs by electric field and each of said plurality of memory cells stores data by a direction of electric polarization.
- 11. A semiconductor integrated circuit device according to claim 10, wherein said nonvolatile memory area stores a program to be performed with said CPU.
- 12. A semiconductor integrated circuit device according to claim 11, wherein said designation circuit includes a register and a comparator,wherein said register stores information for indicating said boundary of said nonvolatile memory area and said volatile memory area, and wherein said comparator compares said information with an address signal outputted from said CPU and outputs a write inhibit signal when an address signal outputted from said CPU is an address of said nonvolatile memory area.
- 13. A semiconductor integrated circuit device according to claim 12, wherein said designation circuit includes a logic circuit which ignores a write control signal outputted from said CPU when said write inhibit signal is outputted from said comparator.
- 14. A semiconductor integrated circuit device according to claim 13, wherein each of memory cells in said volatile memory area operates as a dynamic memory cell.
- 15. A semiconductor integrated circuit device according to claim 14, wherein each of memory cells in said nonvolatile memory area operates as a read only memory cell.
- 16. A semiconductor integrated circuit device according to claim 15, wherein a read operation for reading data stored in each of said memory cells in said nonvolatile memory area is performed without changing a polarity direction of said ferroelectric.
- 17. A microcomputer according to claim 16, wherein said information for indicating said boundary is set when a predetermined operation is confirmed in a debug mode.
- 18. A semiconductor integrated circuit device according to claim 17, wherein said ferroelectric is PZT (PbZrTiO).
- 19. A microcomputer formed on a single semiconductor chip comprising:a CPU; a first nonvolatile memory having a plurality of first memory cells; a second nonvolatile memory having a plurality of second memory cells each of which includes a capacitor including a ferroelectric; and a designation circuit which designates a boundary which divides said nonvolatile memory into a nonvolatile memory area and a volatile memory area, wherein a data change operation of data stored to memory cells in said nonvolatile memory area is prevented and a data change operation of data stored to memory cells in said volatile memory area is permitted, and wherein electric polarization of said ferroelectric of each of said plurality of memory cells occurs by electric field and each of said plurality of memory cells stores data by a direction of electric polarization, and wherein the number of said plurality of second memory cells is more than that of said plurality of first memory cells.
- 20. A microcomputer according to claim 19,wherein said first nonvolatile memory and said nonvolatile memory area of said second nonvolatile memory stores a program to be performed with said CPU.
- 21. A microcomputer according to claim 20, wherein said designation circuit includes a register and a comparator,wherein said register stores information for indicating said boundary of said nonvolatile memory area and said volatile memory area, and wherein said comparator compares said information with an address signal outputted from said CPU and outputs a write inhibit signal when an address signal outputted from said CPU is an address of said nonvolatile memory area.
- 22. A microcomputer according to claim 21, wherein said designation circuit includes a logic circuit which ignores a write control signal outputted from said CPU when said write inhibit signal is outputted from said comparator.
- 23. A microcomputer according to claim 22, wherein each of memory cells in said volatile memory area operates as a dynamic memory cell.
- 24. A microcomputer according to claim 23, wherein each of memory cells in said nonvolatile memory area operates as a read only memory cell.
- 25. A microcomputer according to claim 24, wherein a read operation for reading data stored in each of said memory cells in said second nonvolatile memory area is performed without changing a polarity direction of said ferroelectric.
- 26. A microcomputer according to claim 25, wherein said information for indicating said boundary is set when a predetermined operation is confirmed in a debug mode.
- 27. A microcomputer according to claim 26, wherein said ferroelectric is PZT (PbZrTiO).
- 28. A semiconductor integrated circuit device formed on a single semiconductor chip comprising:a CPU; a first nonvolatile memory having a plurality of first memory cells; a second nonvolatile memory having a plurality of second memory cells each of which includes a capacitor including a ferroelectric; and a designation circuit which designates a boundary which divides said nonvolatile memory into a nonvolatile memory area and a volatile memory area, wherein a data change operation of data stored to memory cells in said nonvolatile memory area is prevented and a data change operation of data stored to memory cells in said volatile memory area is permitted, wherein electric polarization of said ferroelectric of each of said plurality of memory cells occurs by electric field and each of said plurality of memory cells stores data by a direction of electric polarization, and wherein the number of said plurality of second memory cells is more than that of said plurality of first memory cells.
- 29. A semiconductor integrated circuit device according to claim 28, wherein said first nonvolatile memory and said nonvolatile memory area of said second nonvolatile semiconductor memory stores a program to be performed with said CPU.
- 30. A semiconductor integrated circuit device according to claim 29, wherein said designation circuit includes a register and a comparator,wherein said register stores information for indicating said boundary of said nonvolatile memory area and said volatile memory area, and wherein said comparator compares said information with an address signal outputted from said CPU and outputs a write inhibit signal when an address signal outputted from said CPU is an address of said nonvolatile memory area.
- 31. A semiconductor integrated circuit device according to claim 30, wherein said designation circuit includes a logic circuit which ignores a write control signal outputted from said CPU when said write inhibit signal is outputted from said comparator.
- 32. A semiconductor integrated circuit device according to claim 31, wherein each of memory cells in said volatile memory area operates as a dynamic memory cell.
- 33. A semiconductor integrated circuit device according to claim 32, wherein each of memory cells in said nonvolatile memory area operates as a read only memory cell.
- 34. A semiconductor integrated circuit device according to claim 33, wherein a read operation for reading data stored in each of said memory cells in said second nonvolatile memory area is performed without changing a polarity direction of said ferroelectric.
- 35. A semiconductor integrated circuit device according to claim 34, wherein said information for indicating said boundary is set when a predetermined operation is confirmed in a debug mode.
- 36. A semiconductor integrated circuit device according to claim 35, wherein said ferroelectric is PZT (PbZrTiO).
Priority Claims (1)
Number |
Date |
Country |
Kind |
5-282007 |
Oct 1993 |
JP |
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Parent Case Info
This is a continuation application of U.S. Ser. No. 09/203,618, filed Dec. 1, 1998, now U.S. Pat. No. 6,002,856 which is a continuation application of U.S. application Ser. No. 08/769,188, filed on Dec. 18, 1996, now U.S. Pat. No. 5,900,008, which is a continuation of U.S. application Ser. No. 08/295,295, filed Aug. 24, 1994, now abandoned.
US Referenced Citations (23)
Foreign Referenced Citations (1)
Number |
Date |
Country |
61-51659 |
Mar 1986 |
JP |
Non-Patent Literature Citations (1)
Entry |
Shiozaki, Tadashi, “Applying Ferroelectric Thin Film to Integrated Circuits,” Semiconductor World, Dec., 1991, pp. 122-125. (English translation also provided). |
Continuations (3)
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Number |
Date |
Country |
Parent |
09/203618 |
Dec 1998 |
US |
Child |
09/399229 |
|
US |
Parent |
08/769188 |
Dec 1996 |
US |
Child |
09/203618 |
|
US |
Parent |
08/295295 |
Aug 1994 |
US |
Child |
08/769188 |
|
US |