Integrated circuit memory with common address register and decoder

• US 4,811,303 A
• Filed: 11/21/1986
• Issued: 03/07/1989
• Est. Priority Date: 11/22/1985
• Status: Expired due to Fees

• Current Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Original Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Inventors: Hirai, Hayao
• Primary Examiner(s): NOT, DEFINED
• Assistant Examiner(s): Bowler, Alyssa H.
• Application Number:
  US06/933,156
• Time in Patent Office: 837 Days
• Field of Search: 365/189, 365/230, 365/182, 365/218, 365/520, 364/403-406, 235/382.5, 235/382, 235/380, 235/379, 235/492
• US Class Current: 365/185.08
• CPC Class Codes: G11C 11/005 comprising combined but independently operative RAM-ROM, RAM-PROM, RAM-EPROM cells

Abstract

An integrated circuit memory which can be applied, for example, to a memory device of a dialogue type tool information interface for an NC machine tool or a memory unit of various identification cards, comprises a fixed memory unit where necessary information is fixedly stored and the information cannot be rewritten, and a rewrite memory unit where necessary information among information of various sorts supplied from the interface or the card read/write apparatus can be rewritten if necessary, and the fixed memory unit and the rewrite memory unit are integrated in one chip or a single body of one module.

Claims

1. An integrated circuit (IC) memory comprising

a fixed memory unit where necessary information is fixedly stored and the stored information cannot be rewritten;

a rewrite memory unit where necessary information among information of various sorts inputted in the circuit can be rewritten if necessary;

said fixed memory unit and said rewrite memory unit being integrated in one chip;

an information read/write apparatus integrated in the chip and including a common address register with common decoder means for accessing the fixed memory unit and the rewrite memory unit, and a common output buffer means for receiving data read out from locations in the fixed memory unit and the rewrite memory unit accessed by the common decoder means; and

the fixed memory unit and the rewrite memory unit formed into one chip performing information processing of various sorts regarding tools of an NC machine tool, and being assembled as a memory device of a tool system.

2. An integrated circuit memory as set forth in claim 1, wherein the fixed memory unit is constituted by memory cell array of a mask read only memory (MASKROM) having complete nonvolatility nd high reliability in information holding, and the rewrite memory unit is constituted by memory cell array of a static random access memory (SRAM) having access time at high speed and small storage density.

3. An integrated circuit memory as set forth in claim 1, wherein the fixed memory unit is constituted by a programmable read only memory (PROM) which can set the fixed information by performing write operation one time with a mask ROM, and the rewrite memory unit is constituted by an erasable and programmable read only memory (EPROM) which can erase information by irradiation of ultraviolet ray and perform rewrite.

4. An integrated circuit memory as set forth in claim 1, wherein the fixed memory unit is constituted by PROM being programmable, and the rewrite memory unit is constituted by EPROM where stored information can be erased or written, and an electrical erasable and programmable read only memory (E² PROM) which can be rewritten electrically, and SRAM of high speed access.

5. An integrated circuit memory as set forth in claim 1, wherein the fixed memory unit is constituted by PROM being programmable, and the rewrite memory unit is constituted by E² PROM being erasable electrically.

6. An integrated circuit memory as set forth in claim 1, wherein the fixed memory unit is constituted by MASKROM having high reliability and PROM being programmable, and the rewrite memory unit is constituted by EPROM being erasable and written, E² PROM being electrically erasable and written, and SRAM to enable high speed access.

7. An integrated circuit (IC) memory comprising

a fixed memory unit where necessary information is fixedly stored and the stored information cannot be rewritten;

a rewrite memory unit where necessary information among information of various sorts inputted in the circuit can be written if necessary;

said fixed memory unit and said rewrite and unit being integrated in one chip;

an information read/write apparatus integrated in the chip and including a common address register with common decoder means for accessing the fixed memory unit and the rewrite memory unit, and a common output buffer means for receiving data read out from locations in the fixed memory unit and the rewrite memory accessed by the common decoder means; and

the fixed memory unit and the rewrite memory unit formed into one module being constituted as a memory device of an identification card assembled in a plastic card for identifying information of various sorts.

8. An integrated circuit memory as set forth in claim 7, wherein the identification card with the fixed memory unit and the rewrite memory unit assembled therein is used for bank trading, and PROM unit as the fixed memory unit stores information by encoding, such as bank name, personal name, machine name, module name and confidential code, and E² PROM unit as the rewrite memory unit stores information changed corresponding to conditions, such as saving balance, machine working time and module use time.

9. An integrated circuit memory as set forth in claim 7, wherein the fixed memory unit is constituted by memory cell array of a mask read only memory (MASKROM) having complete nonvolatility and high reliability in information holding, and the rewrite memory unit is constituted by memory cell array of a static random access memory (SRAM) having access time at high speed and small storage density.

10. An integrated circuit memory as set forth in claim 7, wherein the fixed memory unit is constituted by a programmable read only memory (PROM) which can set the fixed information by performing write operation one time with a mask ROM, and the rewrite memory unit is constituted by an erasable and programmable read only memory (EPROM) which can erase information by irradiation of ultraviolet ray and perform rewrite.

11. An integrated circuit memory as set forth in claim 7, wherein the fixed memory unit is constituted by PROM being programmable, and the rewrite memory unit is constituted by EPROM where stored information can be erased or written, and an electrical erasable and programmable read only memory (E² PROM) which can be rewritten electrically, and SRAM of high speed access

12. An integrated circuit memory as set forth in claim 7, wherein the fixed memory unit is constituted by PROM being programmable, and the rewrite memory unit is constituted by E² PROM being erasable electrically.

13. An integrated circuit memory as set forth in claim 7, wherein the fixed memory unit is constituted by MASKROM having high reliability and PROM being programmable, and the rewrite memory unit is constituted by EPROM being erasable and written, E² PROM being electrically erasable and written, and SRAM to enable high speed access.