Hitachi, Ltd.

Other

Renesas Technology Corp.

Hitachi Ulsi Systems Co., Ltd.

Hitachi Vlsi Engineering Corp.

Hitachi Ulsi Engineering Corp.

Hitachi Hokkai Semiconductor Ltd.

Hitachi Vsli Engineering Corp.

Hirofumi Mukai

Kiyoshi Matsubara

Masanao Sato

Kenichi Kuroda

Shiro Baba

Kazuyoshi Shiba

Takashi Ito

Masaaki Terasawa

Naoki Yashiki

Eiichi Ishikawa

Naoki Yada

Hiromichi Ishikura

Toshihiro Matsuo

A semiconductor device having an electrically erasable and programmable nonvolatile memory, for example, a rewritable nonvolatile memory including memory cells arranged in rows and columns and disposed to facilitate both flash erasure as well as selective erasure of individual units of plural memory cells. The semiconductor device which functions as a microcomputer chip also has a processing unit and includes an input terminal for receiving an operation mode signal for switching the microcomputer between a first operation mode in which the flash memory is rewritten under control of a processing unit and a second operation mode in which the flash memory is rewritten under control of separate writing circuit externally connectable to the microcomputer.

Data line disturbance free memory block divided flash memory and microcomputer having flash memory therein

A process program such as an erasing/programming program is stored in a boot mat in a nonvolatile memory operational in a boot mode specified after reset start, and a transfer control program for the process program is also stored therein in advance. With an action of setting control information to a predetermined register as trigger, the state of an on-chip CPU is changed from placed in execution of an optional user program to enabled for execution of a transfer control program in the boot mat, and the CPU is returned to the re-execution state of the optional program, after the process program is transferred to an on-chip RAM.

Microcomputer and data processing device

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

Method for manufacturing a printed board on which a semiconductor device having two modes is mounted

Microcomputer including a flash memory that is two-way programmable

A microcomputer is capable of having a CPU calculate a suitable bit rate with respect to a host computer and of setting accordingly an appropriate erasure time forestalling excess erasure of an internally furnished flash memory regardless of the operating frequency of the microcomputer. The microcomputer includes a central processing unit, a non-volatile semiconductor memory, and a terminal which is supplied with a mode set signal. The non-volatile semiconductor memory includes a first block storing a control program and a second block storing data. When the terminal is supplied with a mode set signal for indicating a predetermined mode, if data has previously been written into the second block, such data is erased by the central processing unit. On the other hand, if no data is found in the second block, it is determined that an erase operation is unnecessary and therefore is not performed.

MICROCOMPUTER HAVING A NON-VOLATILE SEMICONDUCTOR MEMORY HAVING A FIRST BLOCK STORING A PROGRAM AND A SECOND BLOCK FOR STORING DATA WHICH IS SELECTIVELY ERASED UNDER PREDETERMINED CONDITIONS IF DATA IS FOUND WRITTEN IN THAT BLOCK

A semiconductor device having and electrically erasable and programmable nonvolatile memory, for example, a rewritable nonvolatile memory including memory cells arranged in rows and columns and disposed to facilitate both flash erasure as well as selective erasure of individual units of plural memory cells. The semiconductor device which functions as a microcomputer chip also has a processing unit and includes an input terminal for receiving an operation mode signal for switching the microcomputer between a first operation mode in which the flash memory is rewritten under control of a processing unit and a second operation mode in which the flash memory is rewritten under control of separate writing circuit externally connectable to the microcomputer.

Method of erasing and programming a flash memory in a single-chip microcomputer having a processing unit and memory

A microcomputer is capable of having a CPU calculate a suitable bit rate with respect to a host computer, and of setting accordingly an appropriate erasure time forestalling excess erasure of an internally furnished flash memory, regardless of the operating frequency of the microcomputer. The erasure time is set according to a number of clock signal cycles calculated by the CPU, based upon a measured number of cycles taken during a predetermined period of receiving serial data from the host computer.

Microcomputer

Growing community of inventors

Musashino, Japan

Hirofumi Mukai