Hitachi Ulsi Systems Co., Ltd.

Renesas Technology Corp.

Other

Hitachi, Ltd.

Renesas Electronics Corporation

Takeo Kanai

Takanori Yamazoe

Toshio Yamada

Yoshio Takazawa

Shinichi Ozawa

Minoru Katoh

Koudou Yamauchi

Toshihiro Araki

Kozo Katayama

Hiroshi Yoshigi

Toshihiro Tanaka

Yutaka Shinagawa

Yoshiaki Kamigaki

Shinichi Minami

Nobutaka Nagasaki

Hiroshi Watase

Masatoshi Takahashi

A semiconductor processing device according to the invention includes a first non-volatile memory () for erasing stored information on a first data length unit, a second non-volatile memory () for erasing stored information on a second data length unit, and a central processing unit (), and capable of inputting/outputting encrypted data from/to an outside. The first non-volatile memory is used for storing an encryption key to be utilized for encrypting the data. The second non-volatile memory is used for storing a program to be processed by the central processing unit. The non-volatile memories to be utilized for storing the program and for storing the encryption key are separated from each other, and the data lengths of the erase units of information to be stored in the non-volatile memories are defined separately. Therefore, the stored information can efficiently be erased before the execution of a processing of writing the program, and the stored information can be erased corresponding to the data length of a necessary processing unit in the write of the encryption key to be utilized in the calculation processing of the CPU.

Semiconductor processing device and IC card

A semiconductor integrated circuit has a memory which can enter active state or standby state, and the memory has voltage generation circuits for bit lines and source lines with which memory cells are connected. The voltage generation circuits make the potential of the bit lines and the potential of the source lines equal to each other in response to an instruction to transition from active state to standby state. The voltage generation circuits produce a potential difference between the bit lines and the source lines in response to an instruction to transition from standby state to active state. In standby state, the potential of the bit lines and that of the source lines are equal to each other. Therefore, sub-threshold leakage does not occur between the source and drain of each memory cell. In active state, the source line potential is not varied.

Semiconductor integrated circuit and IC card

The present invention relates to a booster circuit of a non-volatile memory requiring a plus or minus high voltage equal to or higher than a power-supply voltage. The present invention can generate a high voltage of approximately 12 V even at a low power-supply voltage equal to or lower than 3 V and generate not only a plus high voltage but also a minus high voltage by the same circuit. Also, by combining a body-controlled type parallel charge pump, which is a booster circuit according to the present invention, with a serial-type charge pump, two types of high voltages can be efficiently generated and a reduction in chip areas can be achieved.

Booster circuit

A non-volatile semiconductor memory EEPROM is usually deteriorated depending on the number of times of program and erase operations and application years thereof. A read operation rate of the EEPROM is generally specified to the operation rate considering deterioration of memory and even in the case where the number of times of program and erase operations is rather small and application years are also rather small, the read operation has been conducted at the read operation rate specified considering deterioration of memory. Moreover, when deterioration of memory is advanced exceeding the specified deterioration, the read operation is now disabled in the worst case. In order to overcome such problem, the reference memories are allocated for every erase and program unit block in the EEPROM memory array, the reference memories are also programmed and erased whenever the memories in the block are erased and programmed and the read timing of memory is generated from the read timing of these reference memories. Moreover, the read timing of the reference memories is outputted as an external interface.

Non-volatile semiconductor memory array and method of reading the same memory array

When two bits are stored per memory cell and the two bits are written or read, writing or reading operation has to be performed twice. When a memory array is constructed by using a memory cell, by the access of twice, read time or write time twice as long as conventional read or write time is required. It causes deterioration in speed of a system using the memory. To solve the problem, according to the invention, bit arrangement of a conventional memory cell array is changed according to a writing or reading method With the configuration, a plurality of bytes can be simultaneously written or read by a single access. In order to perform reading at higher speed, a sense amplifier requiring no precharging is also provided.

Non-volatile semiconductor memory device

Growing community of inventors

Kodaira, Japan

Takeo Kanai