The present invention is directed to perform fine low-voltage control without largely increasing the circuit layout area in a low-power consumption structure. In the case of shifting a region to a low-speed mode, a system controller outputs a request signal and an enable signal to a power switch controller and a low-power drive circuit, respectively, to turn off a power switch and to perform a control so that the voltage level of a virtual reference potential becomes about 0.2 V to about 0.3V. The region operates on voltages between a power supply voltage and a virtual reference potential, so that it is controlled in the low-speed mode.

Semiconductor Integrated Circuit Device

An improved automatic placement process for placing logic cells in a universal array. Unused basic units are assigned to rows to reduce the congestion of the wiring in high congestion regions of a universal array. These assigned unused basic units are allocated among rows in a pyramidal manner. Those unused basic units allocated to a given row are distributed along that row in a manner to reduce wiring congestion. During a pair exchange portion of the placement process, quality criteria used for deciding whether to exchange two logic cells on different rows include skipped rows in a node, y-span of a node, minimizing the number of logic cells in excess of two in a node on a row, making a longest row shorter and making longer a shortest row or one which is within a tolerance of being a shortest row.

Logic cell placement method in computer-aided-customization of universal arrays and resulting integrated circuit

A gate array which has power bus routing for increasing current availability to a plurality of transistor cells is provided. The gate array also has separate power busses for input/internal logic and output circuits. The gate array comprises n columns of transistor cells with two power busses extending substantially along each column to power the cells. Input/internal logic power busses and separate output power busses extend around the perimeter of the columns of transistor cells. At least one power strip for increasing current availability to the transistor cells is routed across the transistor cells substantially perpendicular to the n columns and is connected to both the power busses of each column and to the input/internal logic power busses.

Power bus routing for providing noise isolation in gate arrays

A rapid and systematic method for performing chip layout of a random-logic IGFET circuit includes steps for arranging the device features and interconnection features corresponding to the circuit in respective positions in an array of intersecting rows and columns. The method provides layouts of device and interconnection features having a high packing density and a high degree of order and regularity to facilitate checking for layout errors.

Method for fabricating igfet integrated circuits.

A memory array is divided into a plurality of circuit blocks which each include wirings composed of electrically conductive polycrystalline silicon layers and circuit elements that will be operated by signals supplied via the wirings. Each circuit block is served with a signal via an aluminum layer. The signal supplied to the circuit block is transmitted to the circuit elements via an internal wiring. If the aluminum layer is broken, the circuit blocks formed on the remote side beyond the broken portion fail to work properly. Therefore, breakage of the aluminum layer can be easily detected. Further, since signals are supplied to the circuit blocks via an aluminum layer, the memory array operates at increased speeds.

Semiconductor integrated circuit device with memory cells connected to a divided sub-word line

An integrated logic circuit includes an array of insulated gate field effect transistors formed at the crossings of a plurality of substantially parallel first conductor tracks which form the transistor gate electrodes and a plurality of substantially parallel strip-shaped surface regions which form the source and drain electrode regions of the transistors. The field effect transistors of the device include a first group of transistors having a first threshold voltage and a second group of transistors having a second threshold voltage different from the first. In order to make a more compact, easily-designed and easily-manufactured circuit, the conductor tracks and the strip-shaped surface regions form a nonuniform array in which the track and surface regions need not all be of the same length. Further efficiencies are achieved by branching the strip-shaped surface regions where appropriate to implement the desired logic combination.

Aldhous Christopher Jhon

Papers

Integrated logic circuit having interconnections of various lengths between field effect transistors of enhancement and depletion modes