Matsushita Electric Industrial Co., Ltd.

Kiyoto Oota

Tomonori Fujimoto

Yoshihiko Sumimoto

Masataka Kondo

Kazuhiko Shimakawa

Yuji Yamasaki

Masahisa Iida

Kenichi Origasa

Yasuhiro Aoyama

Hakuhei Kawakami

A boosting circuit included in a semiconductor integrated circuit for efficiently stabilizing a boosted potential, including a plurality of boosting circuits and a timing control circuit for distributing the operations of the boosting circuits. Boosting operations per operating cycle of a memory increase in number so as to suppress a reduction in boosted source potential, the reduction being caused by consumption. Moreover, it is possible to perform a boosting operation in a time period equal to that of consuming boosted source potential, resulting in an efficient boosting operation.

Semiconductor circuit having a detection circuit for controlling a power boosting circuit

A semiconductor integrated circuit includes: a first n-well defined in a p-type semiconductor region; word lines; data lines; and a DRAM array. In the array, memory cells are arranged in matrix over the first n-well. Each memory cell includes a p-channel MOS access transistor and a capacitor. The access transistor has its gate connected to an associated one of the word lines, its source connected to an associated one of the data lines and its drain connected to the capacitor. The integrated circuit further includes: a row of sense amplifiers coupled to the data lines; a word line driver for driving the word lines; and a power supply circuit. The power supply circuit receives an external supply voltage, generates internal supply voltages by stepping down the external supply voltage and then applies the internal supply voltages to the sense amplifiers, word line driver and first n-well.

Semiconductor integrated circuit

To realize a semiconductor memory which can be operated at a low frequency without reducing a data transfer rate, the semiconductor memory according to the invention is configured so that a series of operation can be finished in two clock cycles of row address strobe operation and column address strobe operation for operating DRAM. Timing for turning a sense amplifier activation signal SE at a high level after delay time determined by a first delay element since a leading edge of a clock pulse CLK that turns a row address strobe pulse (/RAS) at a low level and activating a sense amplifier sequence is generated. Also, timing for starting read operation and write operation since a leading edge of the clock pulse CLK at which a column address strobe pulse (/CAS) is turned at a low level, turning the sense amplifier activation signal SE at a low level, turning a bit line precharge signal EQPR at a high level and starting precharge operation when the termination of reading and writing is detected is acquired.

Random access memory device

In addition to a pulse train of a refresh request (RRQ) signal requesting for refresh per memory row, a self-refresh mode (SRMOD) signal is applied to a refresh control circuit. As soon as the SRMOD signal makes a transition from LOW to HIGH, an oscillation circuit starts generating a clock pulse train. In response to this clock pulse train, a set pulse is generated. A flip-flop circuit is set by the set pulse and a leading edge of a periodic refresh request (PRRQ) signal pulse is generated. Every time the PRRQ signal becomes HIGH, a reset pulse is generated, the flip-flop circuit is reset by the reset pulse, and a trailing edge of the PRRQ signal pulse is generated. Such arrangement provides a memory having a novel refresh input specification capable of reducing a burden of logic circuits for controlling access of the memory.

Semiconductor memory

A semiconductor device according to the present invention includes: a semiconductor chip; and memory and logic sections formed on the semiconductor chip. The memory section includes: an array of memory cells; a sense amplifier circuit; and memory interconnects respectively provided in a number n (where n is a positive integer) of interconnect layers. The logic section includes logic circuits having logic interconnects respectively provided in a number n+m (where m is a positive integer) of interconnect layers. A metal layer is formed in one of (n+1)th to (n+m)th interconnect layers, covers the array of memory cells and supplies a predetermined potential to the memory section.

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Takatsuki, Japan

Kiyoto Oota