A memory array comprising a matrix of cells each of which includes a pair of bipolar transistor inverters. The collector loads of the inverters are commonly connected to a first constant voltage buss. The emitters of the transistors are commonly connected through a second resistor to a second constant voltage buss. Separate writing and reading circuits are provided for each cell in the array so that array cells can be written into and read from simultaneously.

A dual port memory cell suitable for use in emitter coupled logic applications is accessible from two different address ports. The dual port storage cell includes first and second cross coupled cells, each including a selection conductor and a pair of diodes coupled to the cross coupled transistors to effect selection of that storage cell. The base of each of the cross coupled transistors of the first storage cell is coupled to the base of a coupling transistor, the emitter of which is connected to the base of a corresponding transistor of the other storage cell. Each dual port memory cell has two pairs of bit lines, one pair being coupled to the first storage cell and the other being coupled to the second storage cell. If one of the storage cells is selected, and the other remains unselected, the information in the selected cell is automatically written into the unselected storage cell.

An integratable semi-conductor memory cell has two bipolar transistors which are identical to one another and which have their collectors connected in series with respective circuit parts having a non-linear current characteristic, the respective circuit parts being connected to a first electrical potential. The circuit parts are also connected to the base of the other respective transistor. One emitter of each of the transistors is provided for control by means of logic signals and the invention is particularly characterized in that the circuit part located between the collector of each one of the transistors and a switching point carrying the first electrical potential are selected in such a fashion that the slope dU/dI of the current-voltage characteristic will always be higher than the slope of the corresponding current values in the current-voltage characteristic of the pn-junctions of the emitter-base circuit of both transistors.

Pairs of cross coupled transistors are configured as a bistable regenerative circuit. Isolation means, such as diodes or transistors, are provided in the cross coupling paths to ensure that if the logic state of one transistor is temporarily changed by radiation striking the circuit, the logic state of the other transistor it is paired with will not change and the logic state of the unchanged transistor will be utilized to maintain the logic state of the other pair of transistors. CML, DTL and SDFL circuits are disclosed as the preferred embodiments.

A transistor memory cell is disclosed of the type wherein an unclamped conducting transistor in each of a plurality of memory cells connected to a given word line is driven into saturation when storing data. The cell is equipped with controlled active devices for discharging the saturation capacitance of the conducting transistors prior to writing new data into the cells. Each active device is characterized with a forward low-impedance current direction and reverse high impedance current direction therethrough for each saturation transistor. Each active device is connected to discharge an associated saturation transistor in its forward current direction. In one embodiment, each active device discharges to a word line when the line is brought to an appropriate control potential. In another embodiment, each active device discharges to a separate discharge line not connected to the work line when the former line is brought to an appropriate control potential. The active devices may be diodes. In yet a further embodiment, the active devices may comprise diodes with leaky reverse bias characteristics. These diodes, in their reverse bias current direction, may be used as the memory cell loads. Alternatively, a PNP transistor may be used as the memory cell load. Resistors may be included in the discharge line to prevent word line-bit line voltage clamping.