Electrical computers and digital processing systems: memory – Storage accessing and control – Specific memory composition
Reexamination Certificate
1998-12-22
2001-10-02
Nguyen, Hiep T. (Department: 2187)
Electrical computers and digital processing systems: memory
Storage accessing and control
Specific memory composition
C711S156000, C711S166000, C710S018000, C710S019000, C710S066000, C714S030000
Reexamination Certificate
active
06298412
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a microcomputer using, for example, memories of N (8) bit data width as a single memory of N×M (16) bit data width and a method of determining completion of writing in the microcomputer.
2. Description of the Related Art
Generally, a microcomputer has a built-in mask ROM in which a program for operation control is stored, or a built-in RAM in which data are stored. Further, a nonvolatile memory (flash memory) which can electrically erase written data in a block is well known. Lately, there has been a tendency for a microcomputer to have a built-in nonvolatile memory as a substitute for the mask ROM or the RAM described above. If a nonvolatile memory is built into a microcomputer, due to the capability of nonvolatile memory to enable electrical erasing of written data, it will bring about an advantage that a program for operation control can be rewritten. Thus, cases in which a microcomputer has a built-in nonvolatile memory are increasing.
Microcomputers having a built-in memory of 8 bit data width were mainly used up until recently, but 16-bit type microcomputers have been developed most recently. Among the 16-bit type microcomputers, there is a microcomputer which uses two nonvolatile memories of 8 bit data width arranged in parallel as a single nonvolatile memory of 16 bit data width. In such a microcomputer, there is a case where data are rewritten into the nonvolatile memories on the microcomputer (self-writing).
However, usually in the microcomputer described above, unless the constitution of a microcomputer control section (microcomputer core) is changed to be applicable not to 8 bits, but to 16 bits, the 16 bit type microcomputer cannot be operated. The change of a microcomputer from 8-bit type to 16-bit type requires drastic improvement of the constitution of the microcomputer control section. Especially, program data for self-writing have to be changed drastically so as to be applicable to the 16-bits type microcomputer. Further, such improvement causes an increase of chip area or a fluctuation of circuit characteristics at the time of integration. Thus, a change of circuit is not that easy.
SUMMARY OF THE INVENTION
The purpose of the present invention is to easily realize a microcomputer for M×N bits without causing an increase of chip area or a fluctuation of circuit characteristics even though a microcomputer control section for N bits is used without being modified, in other words, even though a data rewrite program for N bits is used as it is.
The present invention is characterized in that in a microcomputer using M nonvolatile memory devices of N bit data width, which can electrically erase data in a block, as a single memory of N×M bit data width, in a writing mode, data is writing into the M nonvolatile memory devices, and completion of writing is confirmed from the condition of a memory output which is produced using data at the predetermined nth bit from among data to be written into each of the M nonvolatile memory devices.
The present invention is further characterized in that at the time of writing, the memory output is produced by inverting the data at the predetermined nth bit, and when the memory output is inverted to data to be written which have been held beforehand, it will be determined that writing is in progress, and when the memory output becomes non-inverted and non-inverted data coincide with data to be written which have been held beforehand, it will be determined that writing has been completed.
The present invention is further characterized in that in particular, the memory output mentioned above is data at the predetermined nth bit in the final address of an area of each of the nonvolatile memory devices where data are written.
The present invention is further characterized in that in a method of determining completion of writing data into a built-in memory of a microcomputer, the microcomputer uses M, equivalent to two or more, nonvolatile memory devices of N bit data width, which can electrically erase data in a block, as a single memory of N×M bit data width, and in a writing mode, when data to be written are supplied to the M nonvolatile memory devices, a predetermined memory output is produced by extracting at each of the M nonvolatile memory devices data at the predetermined nth bit from among the data to be written; when data, which are read out from the M nonvolatile memory devices after the data to be written were actually written into the M nonvolatile memory devices, coincide with the data to be written which have been held, a condition of the memory output is changed, and the condition of the memory output is monitored, whereby completion of writing the data into the memory is determined.
The present invention is further characterized in that in the method of determining completion of writing data into a built-in memory of a microcomputer, the memory output is inverted data of the extracted data at the predetermined nth bit of each of the M nonvolatile memory devices when the data to be written are supplied to the M nonvolatile memory devices, and non-inverted data of the extracted data at the predetermined nth bit when data, which are read out from the M nonvolatile memory devices after the data to be written are actually written into the M nonvolatile memory devices, coincide with the data to be written which have been held. When the memory output is the inverted data, it will be determined that writing of data into the M nonvolatile memory devices is in progress and when the memory output is the non-inverted data, it will be determined that writing of data into the M nonvolatile memory devices has been completed.
The present invention is further characterized in that in a microcomputer, the microcomputer is a microcomputer using M, equivalent to two or more, nonvolatile memory devices of N bit data width, which can electrically erase data in a block, as a single memory of N×M bit data width, and in a writing mode, when data to be written are supplied to the M nonvolatile memory devices, a predetermined memory output is produced by extracting, at each of the M nonvolatile memory devices, data at the predetermined nth bit from among the data to be written. When data, which are read out from the M nonvolatile memory devices after the data to be written were actually written into the M nonvolatile memory devices, coincide with the data to be written which have been held, a condition of the memory output is changed and the condition of the memory output is monitored, whereby completion of writing the data into the memory is determined.
The present invention is further characterized in that in the microcomputer, the memory output is inverted data of the extracted data at the predetermined nth bit of each of the M nonvolatile memory devices when the data to be written are supplied to the M nonvolatile memory devices, and non-inverted data of the extracted data at the predetermined nth bit when data, which are read out from the M nonvolatile memory devices after the data to be written are actually written into the M nonvolatile memory devices, coincide with the data to be written which have been held. When the memory output is the inverted data, it will be determined that writing of data into the M nonvolatile memory devices is in progress and when the memory output is the non-inverted data, it will be determined that writing of data into the M nonvolatile memory devices has been completed.
The present invention is further characterized in that in a microcomputer, the microcomputer is a microcomputer using M, equivalent to two or more, nonvolatile memory devices of N bit data width, which can electrically erase data in a block, as a single memory of N×M bit data width, and the microcomputer is composed of a data input section to be connected with the nonvolatile memories being capable of outputting data at the predetermined nth bit, a circuit for making output data of the data input section inverted or non-inv
Chigira Kazumasa
Hotaka Kazuo
Kanahori Norimasa
Yatsu Tsunehiko
Hogan & Hartson L.L.P.
Nguyen Hiep T.
Sanyo Electric Co,. Ltd.
LandOfFree
Microcomputer and method of determining completion of... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Microcomputer and method of determining completion of..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Microcomputer and method of determining completion of... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2599404