Abstract: A logical circuit which is capable of serving not only as a shift register but also as counter, comprises a cascade-connection of flip-flops of the same number as the number of bits required. The flip-flops have an input connected to a logical gate group composed of gates which are opened and closed by a shift signal and a count signal. The logical circuit does not require that a flip-flop be included for each shift register part and counter part for each bit, but only requires one flip-flop to perform both the count and shift function. The logical circuit is capable of performing an independent operation of a shift register, an independent operation of a counter and a compound operation of inputting data in a serial fashion for initialization and outputting counted data in a serial fashion.

Abstract: A memory device which is effectively utilized as serial access memory with variable shift length of stored data is disclosed. The memory device comprises memory cells arrayed in a matrix form, a shift register whose output is used for selecting memory cells and control means for varying shift length of the shift register.

Abstract: In utilizing frequency dividers at high frequencies the maximum operating frequency is determined by the delay time through the frequency divider. To minimize this delay time, a digital frequency divider is provided having a binary counter constructed of flip-flops and a shift register coupled to the output of said counter, wherein the output state of the shift register is forcibly reduced to a low level in response to a control signal for varying the number of frequency division of said counter. A circuit is also provided for feeding the input terminal of the flip-flop at the first stage of said counter with an OR output made up of the outputs of said shift register and said counter. Thus, the digital frequency divider can operate at a speed which is limited only by the toggle frequency of said flip-flop circuits.