A dynamic analysis has been made of the behavior of sense signals in large-scale magnetic thin film memories. The timed effects of attenuation, distortion, cross coupling and interconnection are superimposed on the transmitted waveforms. The computed signals can be used as a design guide to determine the length of sense lines, the number of intersecting word lines, the sense amplifier requirements, etc. The key limiting factors are the resistance of lines and the capacitance at the line intersections. Design criteria are discussed.

This paper describes the mutual dependence of interconnection and noise immunity in digital circuitry. Utilizing the charge control concept, the static thresholds of a transistor are defined in terms of the saturation charge and the depletion layer charge. These are subsequently translated into dynamic thresholds of circuitry by means of the network theory. The various noises encountered in digital computers are outlined. The noise due to interconnections is discussed in detail, and remedies are suggested. Design criteria for interconnections are then formulated by selecting the impedance and the routing of the wiring according to the noise margins of the circuits. Engineers are encouraged to view the system as a whole and to treat interconnections as an integral part of circuit design. A numerical example serves to illustrate the important points.

The transmission of digital signals plays an important role in high speed computers, not only because the traveling time on the connecting wire is a significant portion of the total delay, but also because the wire is a distributed parameter coupling network which, as a transmission line, becomes an integral part of the computer circuitry and affects the over-all performance. The classical theories of transmission lines are applied to study the signal waveforms. In the case of low input impedance loads, the radial (or parallel) transmission line scheme should be used. A mathematic relationship can be derived among the ramp slope of signals, the input current to the loads, the length and the impedance of the lines, and the terminations. Then the reflections can be predicted. Guided by this, one chooses the optimum line impedance, the maximum length and the proper termination. For high input impedance loads, the tapped transmission line scheme can be used. The multiple junction reflections are expressed in terms of a series which can be worked out by hand or by machine computation. Likewise, there is a relationship among the impedance of the tapped lines and the feeding line, the spacing of loads and the terminations. There are rules to be followed to decide the transmission scheme.