Renesas Technology Corp.

Hitachi, Ltd.

Hitachi Hokkai Semiconductor Ltd.

Other

Hitachi Ulsi Engineering Corp.

Hitachi Ulsi Systems Co., Ltd.

Eiichi Ishikawa

Naoki Yada

Kiyoshi Matsubara

Masanao Sato

Yasuyuki Saito

Hirofumi Mukai

Shoji Shukuri

Mitsuru Hiraki

A microcomputer capable of on-board programming of dedicated user communication protocols without requiring a serial interface on the mounted board, and that will not destroy the dedicated user communication protocol code even if the system runs out of control. A user boot mat other than a user mat is provided for programming control programs for the user in the on-chip non-volatile memory of the microcomputer. The user boot mat serves as the mat for programming the dedicated user communication protocol and also provides a user boot mode for running the program. The user boot mat cannot program or erase in this user boot mode. By separating the user boot mat and user mat, an interface capable of programming and erasing the user-specified programming can be achieved without having to program a dedicated communication protocol on the user mat.

Microcomputer with configurable communication interfacing

A data processing apparatus supplied a first voltage from outside, includes a CPU, a first voltage generating circuit, a second voltage generating circuit, a clock generating circuit, and, a nonvolatile memory which can be accessed by the CPU. The first voltage generating circuit generates a second voltage, a voltage level of which is lower than that of the first voltage. The clock generating circuit is supplied the second voltage from the first voltage generating circuit and generates a clock signal, and the second voltage generating circuit is supplied the second voltage from the first voltage generating circuit and the clock signal from the clock generating circuit, and generates a second voltage, a voltage level of which is higher than that of the first voltage, for supplying to the nonvolatile memory.

Microcomputer and microprocessor having flash memory operable from single external power supply

The present invention provides a microcomputer wherein in a system which needs to respond to events developed at intervals each shorter than an erase/program process time, erase/programming can be effected on an on-chip non-volatile memory as necessary during its processing. An erase and program control program for an electrically erasable and programmable non-volatile memory is configured inclusive of a loop of the application of a high voltage pulse and data verify or the like, for example. If a program jumped to a subroutine for an address specified by a user is programmed in advance during this loop, then a process by a CPU can be temporarily jumped to the subroutine for the user defined address. Thus, erase and programming can be effected on a system which needs to confirm internal and external events every predetermined intervals or a system with a learning function, or the like during the execution of a user program.

Microcomputer, programming method and erasing method

Microcomputer with mode-controlled memory

A semiconductor processing device is provided which includes a nonvolatile memory unit, a voltage generating unit, and a first terminal. The voltage generating unit generates a first voltage generated from an operation voltage provided from outside of the semiconductor processing device and provides the first voltage to the nonvolatile memory unit for storing data therein. The first terminal provides the first voltage generated by the voltage generating unit to outside of the semiconductor processing device. This first voltage provided to outside of the semiconductor processing device via the first terminal permits checking a voltage level of the first voltage and correcting this voltage level.

A data processing apparatus having a built-in flash memory and being capable of rewriting the built-in flash memory by use of versatilely used PROM writer has a CPU, an electrically rewritable nonvolatile flash memory both formed in a single semiconductor substrate, and is operable in a mode in which the built-in flash memory is rewritable in accordance with commands supplied from a PROM writer. The data processing apparatus has a command latch made externally writable when the above-mentioned operation mode is established, a command analyzer and a sequence controller for controlling a sequence of rewriting the flash memory in accordance with the analysis result. The command analyzer and sequence controller may be realized by the CPU.

Data processing apparatus having a flash memory built-in which is rewritable by use of external device

A microcomputer incorporating a flash memory which is erased and programmed electrically in a stable manner within a relatively wide range of external power supply voltages including those for low-voltage operations. The microcomputer comprises a voltage clamp unit including a reference voltage generating circuit and a constant voltage generating circuit. In operation, the voltage clamp unit generates a voltage of a low dependency on a supply voltage and clamps the generated voltage to a voltage level which, within a tolerable range, is lower than a single supply voltage externally furnished. This prevents voltages boosted by boosting circuits operating on the clamped voltage, i.e., programming and erasure voltages, from being dependent on the externally supplied voltage.

A data processing system () has an erasable and programmable non-volatile memory () and a central processing unit (). The central processing unit allows only a specified partial storage area (Ba) of the non-volatile memory to be intended for a software ECC process. Since ECC codes are added to the partial storage area alone and an error correction is made thereto to thereby increase the number of rewrite assurances, substantially needless waste of each storage area by ECC codes can be avoided as compared with a configuration in which the ECC codes are added to all the write data without distinction regardless of the storage areas. Further, since software copes with ECC processing, ECC correcting capability matched with a device characteristic of the non-volatile memory can easily be selected.

Data processing system and data processing method

A microcomputer incorporating a flash memory which is erased and programmed electrically in a stable manner within a relatively wide range of external power supply voltages including those for low-voltage operations The microcomputer comprises a voltage clamp unit including a reference voltage generating circuit and a constant voltage generating circuit. In operation, the voltage clamp unit generates a voltage of a low dependency on a supply voltage and clamps the generated voltage to a voltage level which, within a tolerable range, is lower than a single supply voltage externally furnished This prevents voltages boosted by boosting circuits operating on the clamped voltage, i.e., programming and erasure voltages, from being dependent on the externally supplied voltage.

Growing community of inventors

Higashimurayama, Japan

Eiichi Ishikawa