Abstract: A semiconductor integrated circuit device endowed with memory circuits achieving high operation margin and low energy consumption with high speed and high integration. Composing a memory cell with a MOSFET having a first threshold voltage corresponding to a first voltage and supplying a selection signal corresponding to said first voltage to a word line by a word driver driven at said first voltage. Corresponding to a second voltage smaller than said first voltage, forming a selection signal sending to said word driver by a decoder comprising MOSFET with a second threshold voltage smaller than said first voltage, operating at said first voltage, and installing a first level shifting circuit including inverter circuits that form a selection signal corresponding to said first voltage by receiving a selection signal corresponding to said second voltage. Thereby, high operation margin and low energy consumption with high speed and high integration can be achieved.

Abstract: An asynchronous control circuit and a semiconductor integrated circuit achieving asynchronous operation and no limitation on the number of ports are offered. In an asynchronous control circuit, by being activated corresponding to at least one access request by acknowledging a plurality of access request signals generated asynchronously to each other and a plurality of input signals corresponding to each of the above-mentioned plurality of access requests, selecting one access request from one or more access requests in the activation mode, acknowledging an input signal corresponding thereto, transmitting the input signal to a memory, acknowledging the input signal corresponding to a non-executed access request after the end the operation corresponding to the input signal, and accessing the aforementioned memory circuit.

Abstract: A semiconductor integrated circuit device endowed with memory circuits achieving high operation margin and low energy consumption with high speed and high integration. Composing a memory cell with a MOSFET having a first threshold voltage corresponding to a first voltage and supplying a selection signal corresponding to said first voltage to a word line by a word driver driven at said first voltage. Corresponding to a second voltage smaller than said first voltage, forming a selection signal sending to said word driver by a decoder comprising MOSFET with a second threshold voltage smaller than said first voltage, operating at said first voltage, and installing a first level shifting circuit including inverter circuits that form a selection signal corresponding to said first voltage by receiving a selection signal corresponding to said second voltage. Thereby, high operation margin and low energy consumption with high speed and high integration can be achieved.

Abstract: To reduce the width of isolation between the first and second p channel MIS•FETs driven by different voltages, a first p channel MIS•FET driven by a first supply voltage and a second p channel MIS•FET driven by a second supply voltage higher than the first supply voltage are arranged in the same n well of the same semiconductor substrate, and the second supply voltage is supplied as a common well bias voltage to the n well.