Control apparatus for controlling memory unit capable of selecting an electrically erasable non-volatile memory and loading information stored therein

• US 5,564,032 A
• Filed: 11/09/1993
• Issued: 10/08/1996
• Est. Priority Date: 11/20/1992
• Status: Expired due to Term

• Current Assignee: Fujitsu Limited
• Original Assignee: Fujitsu Limited
• Inventors: Aota, Masahiro, Nyui, Nozomu, Komatuda, Seiji, Konno, Masahiro, Satoh, Kazuhiro, Hanawa, Tetsuya, Wakayama, Shinichi
• Primary Examiner(s): Kim, Matthew M.
• Application Number:
  US08/149,113
• Time in Patent Office: 1,064 Days
• Field of Search: 364/200 MS File, 364/900 MS File, 364/DIG. 12, 364/ DIG. 2, 395/425, 395/182.03, 395/428, 395/488-489, 395/430, 395/405, 395/492, 395/182.03, 365/900, 365/185
• US Class Current: 711/103
• CPC Class Codes: G11C 16/102 External programming circuits, e.g. EPROM programmers; In-circuit programming or reprogramming; EPROM emulators

Abstract

A control apparatus for controlling a memory unit having an electrically erasable nonvolatile memory for storing information used in a process in an electrical equipment and a flash memory storing a processing program for executing the process in the electrical equipment. The control apparatus includes a loading program for loading information into the flash memory, which program is stored in the electrically erasable nonvolatile memory, a memory selecting circuit for selecting the flash memory when a first selecting information is supplied thereto, and selecting the electrically erasable nonvolatile memory when a second selecting information is supplied thereto, and a loading unit for supplying the second selecting information to the memory selecting circuit under a condition in which a program voltage is supplied from an external power supply thereto and for loading information in accordance with the loading program stored in the electrically erasable nonvolatile memory selected by the memory selecting circuit.

Claims

1. A control apparatus for controlling a memory unit having an electrically erasable nonvolatile memory for storing nonvolatile memory information used in a process in an electrical equipment and a flash memory storing a processing program for executing the process in said electrical equipment, said control apparatus comprising:

a loading program for loading flash memory information into said flash memory, which loading program is stored in said electrically erasable nonvolatile memory;

memory selecting means for selecting said flash memory when a first selecting information is supplied to said memory selecting means, and selecting said electrically erasable nonvolatile memory when a second selecting information is supplied to said memory selecting means;

loading means for supplying the second selecting information to said memory selecting means under a condition in which a program voltage is supplied from an external power supply to said loading means and for loading flash memory information in accordance with the loading program stored in said electrically erasable nonvolatile memory selected by said memory selecting means;

recover information for recovering the loading program stored in said electrically erasable nonvolatile memory, which recovering information is stored in said flash memory;

a control terminal connected to said memory selecting means; and

recover means for recovering the loading program stored in said electrically erasable nonvolatile memory in accordance with the recovering information stored in said flash memory under a condition in which said flash memory is selected by said memory selecting means to which the first selecting information is supplied via said control terminal.

2. The control apparatus as claimed in claim 1, further comprising:

process starting means for initially supplying the second selecting information when said electrical equipment is activated, and for starting a process from a predetermined address of said electrically erasable nonvolatile memory selected by said memory selecting means.

3. The control apparatus as claimed in claim 2, wherein said recover means is activated when said process starting means is not activated.

4. The control apparatus as claimed in claim 1, further comprising:

first determination means for determining, when said electrical equipment is activated, whether or not information stored in said electrically erasable nonvolatile memory malfunctions, wherein said recovery means is activated when said first determination means determines that the information stored in said electrically erasable nonvolatile memory malfunctions.

5. The control apparatus as claimed in claim 1, further comprising:

first determination means for determining, before said loading means performs a process, whether or not information stored in said electrically erasable nonvolatile memory malfunctions, wherein said recover means is activated when said first determination means determines that the information stored in said electrically erasable nonvolatile memory malfunctions.

6. The control apparatus as claimed in claim 1, wherein said control terminal is coupled to a power terminal of said flash memory via a first circuit element by which the first selecting information and the second selecting information are interrupted and through which the program voltage can pass, wherein said control terminal is coupled to said memory selecting means via a second circuit element by which the program voltage is interrupted and through which the first selecting information and the second selecting information can pass, and wherein the program voltage is supplied from said external power supply to said flash memory via said control terminal when information is loaded into said flash memory.

7. The control apparatus as claimed in claim 6, wherein said first circuit element is a diode put between said control terminal and said flash memory such that a direction from said control terminal to said power terminal of said flash memory is a forward direction of said diode.

8. The control apparatus as claimed in claim 6, wherein said second circuit element is a diode put between said control terminal and said memory selecting means such that a direction from said memory selecting means to said control terminal is a forward direction of said diode.

9. The control apparatus as claimed in claim 1, wherein said memory unit is divided into a first memory bank to which said flash memory is assigned and a second memory bank to which said electrically erasable nonvolatile memory is assigned, wherein said memory selecting means has bank switching means outputting a selecting signal, a switching signal having a first level when the first selecting information is supplied to said memory selecting means and having a second level when the second selecting information is supplied to said memory selecting means, so that said flash memory assigned to the first memory bank is selected when said bank switching means outputs the switching signal having the first level and said electrically erasable nonvolatile memory assigned to the second memory bank is selected when said bank switching means outputs the switching signal having a second level.

10. The control apparatus as claimed in claim 1, wherein said electrically erasable nonvolatile memory is an EEPROM.

11. The control apparatus as claimed in claim 1, wherein said control apparatus for controlling said memory unit is provided in a portable telephone set and said electrically erasable nonvolatile memory is used to store telephone numbers.

12. A control apparatus for controlling a memory unit having an electrically erasable nonvolatile memory for storing nonvolatile memory information used in a process in an electrical equipment and a flash memory storing a processing program for executing the process in said electrical equipment, said control apparatus comprising:

a loading program for loading flash memory information into said flash memory, which loading program is stored in said electrically erasable nonvolatile memory;

memory selecting means for selecting said flash memory when a first selecting information is supplied to said memory selecting means, and selecting said electrically erasable nonvolatile memory when a second selecting information is supplied to said memory selecting means;

a first input terminal coupled to a circuit unit in said electrical equipment via a first circuit element by which a program voltage to be supplied to said flash memory is interrupted and through which predetermined information can pass, and coupled to a power terminal of said flash memory via a second circuit element by which said predetermined information is interrupted and through which the program voltage can pass;

loading means for supplying the second selecting information to said memory selecting means under a condition in which a program voltage is supplied from an external power supply to said loading means and for loading information in accordance with the loading program stored in said electrically erasable nonvolatile memory selected by said memory selecting means, wherein said external power supply outputting the program voltage is connected to a second input terminal so that information is loaded into said flash memory by said loading means, and an external equipment outputting the predetermined information to be interrupted by said second circuit element is connected to said second input terminal so that a process is carried out in accordance with the processing program stored in said flash memory in said electrical equipment.

13. The control apparatus as claimed in claim 12, wherein the predetermined information to be interrupted by said second circuit element is represented by a ground potential and by an open state.

14. The control apparatus as claimed in claim 12, wherein said electrically erasable nonvolatile memory is an EEPROM.

15. The control apparatus as claimed in claim 12, wherein said control apparatus for controlling said memory unit is provided in a portable telephone set, and said electrically erasable nonvolatile memory is used to store a telephone number.